torproject/tor

Tor before 0.4.9.7 has an out-of-bounds read by one byte via a malformed BEGIN cell, aka TROVE-2026-007.

Tor before 0.4.9.7 has a NULL pointer dereference when a CERT cell is received out of order, aka TROVE-2026-006.

Tor before 0.4.9.7, when circuit queue memory pressure exists, can experience a client crash because of a double close of a circuit, aka TROVE-2026-009.

Tor before 0.4.9.7 mishandles accounting of the conflux out-of-order queue during the clearing of a queue, aka TROVE-2026-010.

Tor before 0.4.9.7 can attempt or accept BEGIN_DIR via conflux legs, aka TROVE-2026-008.

Tor before 0.4.9.7 has an out-of-bounds read when an END, a TRUNCATE, or a TRUNCATED cell lacks a reason in its payload, aka TROVE-2026-011.

The SafeSocks option in Tor before 0.4.7.13 has a logic error in which the unsafe SOCKS4 protocol can be used but not the safe SOCKS4a protocol, aka TROVE-2022-002.

Tor 0.4.7.x before 0.4.7.8 allows a denial of service via the wedging of RTT estimation.

Tor Browser 9.0.7 on Windows 10 build 10586 is vulnerable to information disclosure. This could allow local attackers to bypass the intended anonymity feature and obtain information regarding the onion services visited by a local user. This can be accomplished by analyzing RAM memory even several hours after the local user used the product. This occurs because the product doesn't properly free memory.

Tor before 0.3.5.16, 0.4.5.10, and 0.4.6.7 mishandles the relationship between batch-signature verification and single-signature verification, leading to a remote assertion failure, aka TROVE-2021-007.

An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-006. The v3 onion service descriptor parsing allows out-of-bounds memory access, and a client crash, via a crafted onion service descriptor

An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-005. Hashing is mishandled for certain retrieval of circuit data. Consequently. an attacker can trigger the use of an attacker-chosen circuit ID to cause algorithm inefficiency.

An issue was discovered in Tor before 0.4.6.5, aka TROVE-2021-003. An attacker can forge RELAY_END or RELAY_RESOLVED to bypass the intended access control for ending a stream.

Tor before 0.4.5.7 allows a remote attacker to cause Tor directory authorities to exit with an assertion failure, aka TROVE-2021-002.

Tor before 0.4.5.7 allows a remote participant in the Tor directory protocol to exhaust CPU resources on a target, aka TROVE-2021-001.

Tor before 0.4.3.6 has an out-of-bounds memory access that allows a remote denial-of-service (crash) attack against Tor instances built to use Mozilla Network Security Services (NSS), aka TROVE-2020-001.

Tor before 0.3.5.10, 0.4.x before 0.4.1.9, and 0.4.2.x before 0.4.2.7 allows remote attackers to cause a Denial of Service (memory leak), aka TROVE-2020-004. This occurs in circpad_setup_machine_on_circ because a circuit-padding machine can be negotiated twice on the same circuit.

Tor before 0.3.5.10, 0.4.x before 0.4.1.9, and 0.4.2.x before 0.4.2.7 allows remote attackers to cause a Denial of Service (CPU consumption), aka TROVE-2020-002.

The daemon in Tor through 0.4.1.8 and 0.4.2.x through 0.4.2.6 does not verify that a rendezvous node is known before attempting to connect to it, which might make it easier for remote attackers to discover circuit information. NOTE: The network team of Tor claims this is an intended behavior and not a vulnerability

The Hidden Service (HS) client implementation in Tor before 0.2.4.27, 0.2.5.x before 0.2.5.12, and 0.2.6.x before 0.2.6.7 allows remote servers to cause a denial of service (assertion failure and application exit) via a malformed HS descriptor.

Tor before 0.2.4.26 and 0.2.5.x before 0.2.5.11 does not properly handle pending-connection resolve states during periods of high DNS load, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via crafted packets.

buf_pullup in Tor before 0.2.4.26 and 0.2.5.x before 0.2.5.11 does not properly handle unexpected arrival times of buffers with invalid layouts, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via crafted packets.

The Hidden Service (HS) server implementation in Tor before 0.2.4.27, 0.2.5.x before 0.2.5.12, and 0.2.6.x before 0.2.6.7 allows remote attackers to cause a denial of service (assertion failure and daemon exit) via unspecified vectors.

In Tor before 0.3.3.12, 0.3.4.x before 0.3.4.11, 0.3.5.x before 0.3.5.8, and 0.4.x before 0.4.0.2-alpha, remote denial of service against Tor clients and relays can occur via memory exhaustion in the KIST cell scheduler.

A use-after-free vulnerability in SVG Animation has been discovered. An exploit built on this vulnerability has been discovered in the wild targeting Firefox and Tor Browser users on Windows. This vulnerability affects Firefox < 50.0.2, Firefox ESR < 45.5.1, and Thunderbird < 45.5.1.

A use-after-free issue was discovered in Tor 0.3.2.x before 0.3.2.10. It allows remote attackers to cause a denial of service (relay crash) because the KIST implementation allows a channel to be added more than once in the pending list.

An issue was discovered in Tor before 0.2.9.15, 0.3.1.x before 0.3.1.10, and 0.3.2.x before 0.3.2.10. The directory-authority protocol-list subprotocol implementation allows remote attackers to cause a denial of service (NULL pointer dereference and directory-authority crash) via a misformatted relay descriptor that is mishandled during voting.

Tor before 0.2.8.12 might allow remote attackers to cause a denial of service (client crash) via a crafted hidden service descriptor.

In Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before 0.2.9.14, 0.3.0 before 0.3.0.13, and 0.3.1 before 0.3.1.9, there is a use-after-free in onion service v2 during intro-point expiration because the expiring list is mismanaged in certain error cases, aka TROVE-2017-013.

In Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before 0.2.9.14, 0.3.0 before 0.3.0.13, and 0.3.1 before 0.3.1.9, the replay-cache protection mechanism is ineffective for v2 onion services, aka TROVE-2017-009. An attacker can send many INTRODUCE2 cells to trigger this issue.

In Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before 0.2.9.14, 0.3.0 before 0.3.0.13, and 0.3.1 before 0.3.1.9, remote attackers can cause a denial of service (NULL pointer dereference and application crash) against directory authorities via a malformed descriptor, aka TROVE-2017-010.

In Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before 0.2.9.14, 0.3.0 before 0.3.0.13, and 0.3.1 before 0.3.1.9, an attacker can cause a denial of service (application hang) via crafted PEM input that signifies a public key requiring a password, which triggers an attempt by the OpenSSL library to ask the user for the password, aka TROVE-2017-011.

In Tor before 0.2.5.16, 0.2.6 through 0.2.8 before 0.2.8.17, 0.2.9 before 0.2.9.14, 0.3.0 before 0.3.0.13, and 0.3.1 before 0.3.1.9, relays (that have incompletely downloaded descriptors) can pick themselves in a circuit path, leading to a degradation of anonymity, aka TROVE-2017-012.

Tor Browser before 7.0.9 on macOS and Linux allows remote attackers to bypass the intended anonymity feature and discover a client IP address via vectors involving a crafted web site that leverages file:// mishandling in Firefox, aka TorMoil. NOTE: Tails is unaffected.

The rend_service_intro_established function in or/rendservice.c in Tor before 0.2.8.15, 0.2.9.x before 0.2.9.12, 0.3.0.x before 0.3.0.11, 0.3.1.x before 0.3.1.7, and 0.3.2.x before 0.3.2.1-alpha, when SafeLogging is disabled, allows attackers to obtain sensitive information by leveraging access to the log files of a hidden service, because uninitialized stack data is included in an error message about construction of an introduction point circuit.

Tor 0.3.x before 0.3.0.9 has a guard-selection algorithm that only considers the exit relay (not the exit relay's family), which might allow remote attackers to defeat intended anonymity properties by leveraging the existence of large families.

The hidden-service feature in Tor before 0.3.0.8 allows a denial of service (assertion failure and daemon exit) in the relay_send_end_cell_from_edge_ function via a malformed BEGIN cell.

The hidden-service feature in Tor before 0.3.0.8 allows a denial of service (assertion failure and daemon exit) in the connection_edge_process_relay_cell function via a BEGIN_DIR cell on a rendezvous circuit.

Tor before 0.2.8.9 and 0.2.9.x before 0.2.9.4-alpha had internal functions that were entitled to expect that buf_t data had NUL termination, but the implementation of or/buffers.c did not ensure that NUL termination was present, which allows remote attackers to cause a denial of service (client, hidden service, relay, or authority crash) via crafted data.

Tor before 0.2.4.23 and 0.2.5 before 0.2.5.6-alpha maintains a circuit after an inbound RELAY_EARLY cell is received by a client, which makes it easier for remote attackers to conduct traffic-confirmation attacks by using the pattern of RELAY and RELAY_EARLY cells as a means of communicating information about hidden service names.

Tor before 0.2.3.23-rc allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a renegotiation attempt that occurs after the initiation of the V3 link protocol.

Tor before 0.2.3.24-rc allows remote attackers to cause a denial of service (assertion failure and daemon exit) by performing link protocol negotiation incorrectly.

Tor before 0.2.4.20, when OpenSSL 1.x is used in conjunction with a certain HardwareAccel setting on Intel Sandy Bridge and Ivy Bridge platforms, does not properly generate random numbers for (1) relay identity keys and (2) hidden-service identity keys, which might make it easier for remote attackers to bypass cryptographic protection mechanisms via unspecified vectors.

The connection_edge_process_relay_cell function in or/relay.c in Tor before 0.2.3.25 maintains circuits even if an unexpected SENDME cell arrives, which might allow remote attackers to cause a denial of service (memory consumption or excessive cell reception rate) or bypass intended flow-control restrictions via a RELAY_COMMAND_SENDME command.

The tor_timegm function in common/util.c in Tor before 0.2.2.39, and 0.2.3.x before 0.2.3.22-rc, does not properly validate time values, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a malformed directory object, a different vulnerability than CVE-2012-4419.

The compare_tor_addr_to_addr_policy function in or/policies.c in Tor before 0.2.2.39, and 0.2.3.x before 0.2.3.21-rc, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a zero-valued port field that is not properly handled during policy comparison.

routerlist.c in Tor before 0.2.2.38 uses a different amount of time for relay-list iteration depending on which relay is chosen, which might allow remote attackers to obtain sensitive information about relay selection via a timing side-channel attack.

The networkstatus_parse_vote_from_string function in routerparse.c in Tor before 0.2.2.38 does not properly handle an invalid flavor name, which allows remote attackers to cause a denial of service (out-of-bounds read and daemon crash) via a crafted (1) vote document or (2) consensus document.

Use-after-free vulnerability in dns.c in Tor before 0.2.2.38 might allow remote attackers to cause a denial of service (daemon crash) via vectors related to failed DNS requests.

Tor before 0.2.2.34, when configured as a bridge, uses direct DirPort access instead of a Tor TLS connection for a directory fetch, which makes it easier for remote attackers to enumerate bridges by observing DirPort connections.

Tor before 0.2.2.34, when configured as a bridge, sets up circuits through a process different from the process used by a client, which makes it easier for remote attackers to enumerate bridges by observing circuit building.

Tor before 0.2.2.24-alpha continues to use a reachable bridge that was previously configured but is not currently configured, which might allow remote attackers to obtain sensitive information about clients in opportunistic circumstances by monitoring network traffic to the bridge port.

Tor before 0.2.2.25-alpha, when configured as a relay without the Nickname configuration option, uses the local hostname as the Nickname value, which allows remote attackers to obtain potentially sensitive information by reading this value.

Multiple heap-based buffer overflows in Tor before 0.2.2.35 allow remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code by (1) establishing a SOCKS connection to SocksPort or (2) leveraging a SOCKS proxy configuration.

Tor before 0.2.2.34, when configured as a bridge, accepts the CREATE and CREATE_FAST values in the Command field of a cell within an OR connection that it initiated, which allows remote relays to enumerate bridges by using these values.

Tor before 0.2.2.34, when configured as a client or bridge, sends a TLS certificate chain as part of an outgoing OR connection, which allows remote relays to bypass intended anonymity properties by reading this chain and then determining the set of entry guards that the client or bridge had selected.

Buffer overflow in the policy_summarize function in or/policies.c in Tor before 0.2.1.30 allows remote attackers to cause a denial of service (directory authority crash) via a crafted policy that triggers creation of a long port list.

Tor before 0.2.1.29 and 0.2.2.x before 0.2.2.21-alpha might allow remote attackers to cause a denial of service (assertion failure and daemon exit) via vectors related to malformed router caches and improper handling of integer values.

The tor_realloc function in Tor before 0.2.1.29 and 0.2.2.x before 0.2.2.21-alpha does not validate a certain size value during memory allocation, which might allow remote attackers to cause a denial of service (daemon crash) via unspecified vectors, related to "underflow errors."

Tor before 0.2.1.29 and 0.2.2.x before 0.2.2.21-alpha allows remote attackers to cause a denial of service (assertion failure and daemon exit) via blobs that trigger a certain file size, as demonstrated by the cached-descriptors.new file.

Heap-based buffer overflow in Tor before 0.2.1.29 and 0.2.2.x before 0.2.2.21-alpha allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via unspecified vectors.

Tor before 0.2.1.29 and 0.2.2.x before 0.2.2.21-alpha makes calls to Libevent within Libevent log handlers, which might allow remote attackers to cause a denial of service (daemon crash) via vectors that trigger certain log messages.

Tor before 0.2.1.29 and 0.2.2.x before 0.2.2.21-alpha does not properly manage key data in memory, which might allow local users to obtain sensitive information by leveraging the ability to read memory that was previously used by a different process.

Tor before 0.2.1.29 and 0.2.2.x before 0.2.2.21-alpha does not properly check the amount of compression in zlib-compressed data, which allows remote attackers to cause a denial of service via a large compression factor.

Heap-based buffer overflow in Tor before 0.2.1.28 and 0.2.2.x before 0.2.2.20-alpha allows remote attackers to cause a denial of service (daemon crash) or possibly execute arbitrary code via unspecified vectors.

Tor 0.2.2.x before 0.2.2.7-alpha, when functioning as a directory mirror, does not prevent logging of the client IP address upon detection of erroneous client behavior, which might make it easier for local users to discover the identities of clients in opportunistic circumstances by reading log files.

Tor before 0.2.1.22, and 0.2.2.x before 0.2.2.7-alpha, when functioning as a bridge directory authority, allows remote attackers to obtain sensitive information about bridge identities and bridge descriptors via a dbg-stability.txt directory query.

Tor before 0.2.1.22, and 0.2.2.x before 0.2.2.7-alpha, uses deprecated identity keys for certain directory authorities, which makes it easier for man-in-the-middle attackers to compromise the anonymity of traffic sources and destinations.

The connection_edge_process_relay_cell_not_open function in src/or/relay.c in Tor 0.2.x before 0.2.0.35 and 0.1.x before 0.1.2.8-beta allows exit relays to have an unspecified impact by causing controllers to accept DNS responses that redirect to an internal IP address via unknown vectors. NOTE: some of these details are obtained from third party information.

Tor before 0.2.0.35 allows remote attackers to cause a denial of service (application crash) via a malformed router descriptor.

Tor before 0.2.0.34 treats incomplete IPv4 addresses as valid, which has unknown impact and attack vectors related to "Spec conformance," as demonstrated using 192.168.0.

Unspecified vulnerability in Tor before 0.2.0.34 allows directory mirrors to cause a denial of service (exit node crash) via "malformed input."

Unspecified vulnerability in Tor before 0.2.0.34 allows directory mirrors to cause a denial of service via unknown vectors.

Unspecified vulnerability in Tor before 0.2.0.34 allows attackers to cause a denial of service (infinite loop) via "corrupt votes."

Tor 0.2.0.28, and probably 0.2.0.34 and earlier, allows remote attackers, with control of an entry router and an exit router, to confirm that a sender and receiver are communicating via vectors involving (1) replaying, (2) modifying, (3) inserting, or (4) deleting a single cell, and then observing cell recognition errors at the exit router. NOTE: the vendor disputes the significance of this issue, noting that the product's design "accepted end-to-end correlation as an attack that is too expensive to solve."

Unspecified vulnerability in Tor before 0.2.0.33 has unspecified impact and remote attack vectors that trigger heap corruption.

Tor before 0.2.0.32 does not properly process the ClientDNSRejectInternalAddresses configuration option in situations where an exit relay issues a policy-based refusal of a stream, which allows remote exit relays to have an unknown impact by mapping an internal IP address to the destination hostname of a refused stream.

Tor before 0.2.0.32 does not properly process the (1) User and (2) Group configuration options, which might allow local users to gain privileges by leveraging unintended supplementary group memberships of the Tor process.

Tor before 0.1.2.16, when ControlPort is enabled, does not properly restrict commands to localhost port 9051, which allows remote attackers to modify the torrc configuration file, compromise anonymity, and have other unspecified impact via HTTP POST data containing commands without valid authentication, as demonstrated by an HTML form (1) hosted on a web site or (2) injected by a Tor exit node.

Tor before 0.1.2.15 can select a guard node beyond the first listed never-before-connected-to guard node, which allows remote attackers with control of certain guard nodes to obtain sensitive information and possibly leverage further attacks.

Tor before 0.1.2.15 does not properly distinguish "streamids from different exits," which might allow remote attackers with control over Tor routers to inject cells into arbitrary streams.

Tor before 0.1.2.15 sends "destroy cells" containing the reason for tearing down a circuit, which allows remote attackers to obtain sensitive information, contrary to specifications.

Buffer overflow in Tor before 0.1.2.15, when using BSD natd support, allows remote attackers to cause a denial of service via unspecified vectors.

Tor before 0.1.2.14 can construct circuits in which an entry guard is in the same family as the exit node, which might compromise the anonymity of traffic sources and destinations by exposing traffic to inappropriate remote observers.

Tor does not verify a node's uptime and bandwidth advertisements, which allows remote attackers who operate a low resource node to make false claims of greater resources, which places the node into use for many circuits and compromises the anonymity of traffic sources and destinations.

Tor allows remote attackers to discover the IP address of a hidden service by accessing this service at a high rate, thereby changing the server's CPU temperature and consequently changing the pattern of time values visible through (1) ICMP timestamps, (2) TCP sequence numbers, and (3) TCP timestamps, a different vulnerability than CVE-2006-0414. NOTE: it could be argued that this is a laws-of-physics vulnerability that is a fundamental design limitation of certain hardware implementations, so perhaps this issue should not be included in CVE.

Unspecified vulnerability in (1) Tor 0.1.0.x before 0.1.0.18 and 0.1.1.x before 0.1.1.23, and (2) ScatterChat before 1.0.2, allows remote attackers operating a Tor entry node to route arbitrary Tor traffic through clients or cause a denial of service (flood) via unspecified vectors.

Tor before 0.1.1.20 uses OpenSSL pseudo-random bytes (RAND_pseudo_bytes) instead of cryptographically strong RAND_bytes, and seeds the entropy value at start-up with 160-bit chunks without reseeding, which makes it easier for attackers to conduct brute force guessing attacks.

The privoxy configuration file in Tor before 0.1.1.20, when run on Apple OS X, logs all data via the "logfile", which allows attackers to obtain potentially sensitive information.

Tor before 0.1.1.20 does not validate that a server descriptor's fingerprint line matches its identity key, which allows remote attackers to spoof the fingerprint line, which might be trusted by users or other applications.

Tor client before 0.1.1.20 prefers entry points based on is_fast or is_stable flags, which could allow remote attackers to be preferred over nodes that are identified as more trustworthy "entry guard" (is_guard) systems by directory authorities.

Tor before 0.1.1.20 kills the circuit when it receives an unrecognized relay command, which causes network circuits to be disbanded. NOTE: while this item is listed under the "Security fixes" section of the developer changelog, the developer clarified on 20060707 that this is only a self-DoS. Therefore this issue should not be included in CVE

Tor before 0.1.1.20 uses improper logic to validate the "OR" destination, which allows remote attackers to perform a man-in-the-middle (MITM) attack via unspecified vectors.

Tor before 0.1.1.20 supports server descriptors that contain hostnames instead of IP addresses, which allows remote attackers to arbitrarily group users by providing preferential address resolution.

Tor before 0.1.1.20 allows remote attackers to spoof log entries or possibly execute shell code via strings with non-printable characters.

Tor before 0.1.1.20 does not sufficiently obey certain firewall options, which allows remote attackers to bypass intended access restrictions for dirservers, direct connections, or proxy servers.

TLS handshakes in Tor before 0.1.1.20 generate public-private keys based on TLS context rather than the connection, which makes it easier for remote attackers to conduct brute force attacks on the encryption keys.

Tor before 0.1.1.20 creates "internal circuits" primarily consisting of nodes with "useful exit nodes," which allows remote attackers to conduct unspecified statistical attacks.

Integer overflow in Tor before 0.1.1.20 allows remote attackers to execute arbitrary code via crafted large inputs, which result in a buffer overflow when elements are added to smartlists.

Unspecified vulnerability in the directory server (dirserver) in Tor before 0.1.1.20 allows remote attackers to cause an unspecified denial of service via unknown vectors.

Tor before 0.1.1.20 allows remote attackers to identify hidden services via a malicious Tor server that attempts a large number of accesses of the hidden service, which eventually causes a circuit to be built through the malicious server.

Tor 0.1.0.13 and earlier, and experimental versions 0.1.1.4-alpha and earlier, does not reject certain weak keys when using ephemeral Diffie-Hellman (DH) handshakes, which allows malicious Tor servers to obtain the keys that a client uses for other systems in the circuit.

Unknown vulnerability in Tor before 0.1.0.10 allows remote attackers to read arbitrary memory and possibly key information from the exit server's process space.