RUB-NDS/Johnny-You-Are-Fired

The signature verification routine in the Airmail GPG-PGP Plugin, versions 1.0 (9) and earlier, does not verify the status of the signature at all, which allows remote attackers to spoof arbitrary email signatures by crafting a signed email with an invalid signature. Also, it does not verify the validity of the signing key, which allows remote attackers to spoof arbitrary email signatures by crafting a key with a fake user ID (email address) and injecting it into the user's keyring.

The signature verification routine in install.sh in yarnpkg/website through 2018-06-05 only verifies that the yarn release is signed by any (arbitrary) key in the local keyring of the user, and does not pin the signature to the yarn release key, which allows remote attackers to sign tampered yarn release packages with their own key.

A flaw during verification of certain S/MIME signatures causes emails to be shown in Thunderbird as having a valid digital signature, even if the shown message contents aren't covered by the signature. The flaw allows an attacker to reuse a valid S/MIME signature to craft an email message with arbitrary content. This vulnerability affects Thunderbird < 60.5.1.

Enigmail before 2.0.6 is prone to to OpenPGP signatures being spoofed for arbitrary messages using a PGP/INLINE signature wrapped within a specially crafted multipart HTML email.

GNOME Evolution through 3.28.2 is prone to OpenPGP signatures being spoofed for arbitrary messages using a specially crafted email that contains a valid signature from the entity to be impersonated as an attachment.

MailMate before 1.11.3 mishandles a suspicious HTML/MIME structure in a signed/encrypted email.

An issue was discovered in password-store.sh in pass in Simple Password Store 1.7.x before 1.7.2. The signature verification routine parses the output of GnuPG with an incomplete regular expression, which allows remote attackers to spoof file signatures on configuration files and extension scripts. Modifying the configuration file allows the attacker to inject additional encryption keys under their control, thereby disclosing passwords to the attacker. Modifying the extension scripts allows the attacker arbitrary code execution.

The signature verification routine in Enigmail before 2.0.7 interprets user ids as status/control messages and does not correctly keep track of the status of multiple signatures, which allows remote attackers to spoof arbitrary email signatures via public keys containing crafted primary user ids.

mainproc.c in GnuPG before 2.2.8 mishandles the original filename during decryption and verification actions, which allows remote attackers to spoof the output that GnuPG sends on file descriptor 2 to other programs that use the "--status-fd 2" option. For example, the OpenPGP data might represent an original filename that contains line feed characters in conjunction with GOODSIG or VALIDSIG status codes.

An issue was discovered in Enigmail before 1.9.9. In a variant of CVE-2017-17847, signature spoofing is possible for multipart/related messages because a signed message part can be referenced with a cid: URI but not actually displayed. In other words, the entire containing message appears to be signed, but the recipient does not see any of the signed text.