Gnupg

In GnuPG before 2.5.17, a crafted CMS (S/MIME) EnvelopedData message carrying an oversized wrapped session key can cause a stack-based buffer overflow in gpg-agent during PKDECRYPT--kem=CMS handling. This can easily be leveraged for denial of service; however, there is also memory corruption that could lead to remote code execution.Show less

In GnuPG before 2.4.9, armor_filter in g10/armor.c has two increments of an index variable where one is intended, leading to an out-of-bounds write for crafted input. (For ExtendedLTS, 2.2.51 and later are fixed versions.)Show less

In GnuPG through 2.4.8, if a signed message has \f at the end of a plaintext line, an adversary can construct a modified message that places additional text after the signed material, such that signature verification of the modified message succeeds (although an "invalid armor" message is printed during verification). This is related to use of \f as a marker to denote truncation of a long plaintext line.Show less

In GnuPG before 2.5.5, if a user chooses to import a certificate with certain crafted subkey data that lacks a valid backsig or that has incorrect usage flags, the user loses the ability to verify signatures made from certain other signing keys, aka a "verification DoS."Show less

A vulnerability was found in the Libksba library due to an integer overflow within the CRL parser. The vulnerability can be exploited remotely for code execution on the target system by passing specially crafted data to the application, for example, a malicious S/MIME attachment.Show less

GnuPG through 2.3.6, in unusual situations where an attacker possesses any secret-key information from a victim's keyring and other constraints (e.g., use of GPGME) are met, allows signature forgery via injection into the status line.Show less

The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.Show less

Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm, and the window size is not chosen appropriately. This, for example, affects use of ElGamal in OpenPGP.Show less

GnuPG 2.2.21 and 2.2.22 (and Gpg4win 3.1.12) has an array overflow, leading to a crash or possibly unspecified other impact, when a victim imports an attacker's OpenPGP key, and this key has AEAD preferences. The overflow is caused by a g10/key-check.c error. NOTE: GnuPG 2.3.x is unaffected. GnuPG 2.2.23 is a fixed version.Show less

A flaw was found in the way certificate signatures could be forged using collisions found in the SHA-1 algorithm. An attacker could use this weakness to create forged certificate signatures. This issue affects GnuPG versions before 2.2.18.Show less

The mpi_powm function in Libgcrypt before 1.6.3 and GnuPG before 1.4.19 allows attackers to obtain sensitive information by leveraging timing differences when accessing a pre-computed table during modular exponentiation, related to a "Last-Level Cache Side-Channel Attack."Show less

Libgcrypt before 1.6.3 and GnuPG before 1.4.19 does not implement ciphertext blinding for Elgamal decryption, which allows physically proximate attackers to obtain the server's private key by determining factors using crafted ciphertext and the fluctuations in the electromagnetic field during multiplication.Show less

kbx/keybox-search.c in GnuPG before 1.4.19, 2.0.x before 2.0.27, and 2.1.x before 2.1.2 does not properly handle bitwise left-shifts, which allows remote attackers to cause a denial of service (invalid read operation) via a crafted keyring file, related to sign extensions and "memcpy with overlapping ranges."Show less