TigerVNC/tigervnc

In TigerVNC before 1.16.2, Image.cxx in x0vncserver allows other users to observe or manipulate the screen contents, or cause an application crash, because of incorrect permissions.

In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers mishandle TLS certificate exceptions. They store the certificates as authorities, meaning that the owner of a certificate could impersonate any server after a client had added an exception.

Multiple heap-based buffer overflows in the ZRLE_DECODE function in common/rfb/zrleDecode.h in TigerVNC before 1.3.1, when NDEBUG is enabled, allow remote VNC servers to cause a denial of service (vncviewer crash) and possibly execute arbitrary code via vectors related to screen image rendering.

TigerVNC version prior to 1.10.1 is vulnerable to stack buffer overflow, which could be triggered from CMsgReader::readSetCursor. This vulnerability occurs due to insufficient sanitization of PixelFormat. Since remote attacker can choose offset from start of the buffer to start writing his values, exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

TigerVNC version prior to 1.10.1 is vulnerable to stack use-after-return, which occurs due to incorrect usage of stack memory in ZRLEDecoder. If decoding routine would throw an exception, ZRLEDecoder may try to access stack variable, which has been already freed during the process of stack unwinding. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which could be triggered from DecodeManager::decodeRect. Vulnerability occurs due to the signdness error in processing MemOutStream. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which occurs in TightDecoder::FilterGradient. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow. Vulnerability could be triggered from CopyRectDecoder due to incorrect value checks. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

In TigerVNC 1.7.1 (SSecurityVeNCrypt.cxx SSecurityVeNCrypt::SSecurityVeNCrypt), an unauthenticated client can cause a small memory leak in the server.

In TigerVNC 1.7.1 (CConnection.cxx CConnection::CConnection), an unauthenticated client can cause a small memory leak in the server.

In TigerVNC 1.7.1 (SMsgReader.cxx SMsgReader::readClientCutText), by causing an integer overflow, an authenticated client can crash the server.

In TigerVNC 1.7.1 (SSecurityPlain.cxx SSecurityPlain::processMsg), unauthenticated users can crash the server by sending long usernames.

In TigerVNC 1.7.1 (VNCSConnectionST.cxx VNCSConnectionST::fence), an authenticated client can cause a double free, leading to denial of service or potentially code execution.

Buffer overflow in the ModifiablePixelBuffer::fillRect function in TigerVNC before 1.7.1 allows remote servers to execute arbitrary code via an RRE message with subrectangle outside framebuffer boundaries.

The Xvnc server in TigerVNC allows remote attackers to cause a denial of service (invalid memory access and crash) by terminating a TLS handshake early.