ELA-1610-1 gnupg2 security update

memory corruption

2026-01-14
Packagegnupg2
Version2.1.18-8~deb9u6 (stretch), 2.2.12-1+deb10u3 (buster)
Related CVEs CVE-2025-68973


Several issues have been discovered in gnupg2, a tool for secure communication and data storage.

CVE-2025-68973

There exist memory corruptions in the armor parsing code of GnuPG
that can be exploited to provide primitives like out of bounds
buffer read and write. This might be exploitable to the point of
remote code execution (RCE).

Additional issues:

+ Potential key signature digest algorithm downgrade.

  GnuPG may downgrade the message digest algorithm to insecure SHA1
  algorithm during signature checking due to reading from
  uninitialized memory. This reduces the security of User ID
  Certification Signatures to that of SHA1. SHA1 suffers from known
  cryptographic weaknesses like chosen prefix attacks.

+ Multiple plaintext attack on detached PGP signatures.

  An attacker can arbitrarily swap the plaintext shown to a GnuPG
  user, when the user verifies a detached signature versus views it
  with `--decrypt`. This attack allows deceiving users verifying
  messages, following GnuPG usage best practices about the content
  of a message signed with a detached signature. Note, that it is
  possible in many scenarios to convert between signature types,
  i.e., convert a different signature type to a detached signature.

+ GnuPG Accepts Path Separators and Path Traversals in Literal Data.

  GnuPG accepts arbitrary file paths in the unsigned Literal Data
  packet filename field and uses that value without sufficient
  sanitization. In combination with tricking a user with ANSI
  formatted output that changes GnuPG output with deceptive apparent
  GnuPG logs, this can lead to creation or overwrite of any file on
  the system the user can write to, including executable files which
  the user may later execute.


For Debian 10 buster, these problems have been fixed in version 2.2.12-1+deb10u3.

For Debian 9 stretch, these problems have been fixed in version 2.1.18-8~deb9u6.

We recommend that you upgrade your gnupg2 packages.

Further information about Extended LTS security advisories can be found in the dedicated section of our website.