Ubuntu 4.10 / 5.04 / 5.10 : gnupg vulnerability (USN-252-1)
Medium Nessus Plugin ID 21071
SynopsisThe remote Ubuntu host is missing a security-related patch.
DescriptionTavis Ormandy discovered a potential weakness in the signature verification of gnupg. gpgv and gpg --verify returned a successful exit code even if the checked file did not have any signature at all.
The recommended way of checking the result is to evaluate the status messages, but some third-party applications might just check the exit code for determining whether or not a signature is valid. These applications could be tricked into erroneously reporting a valid signature.
Please note that this does not affect the Ubuntu package signature checks.
Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpdate the affected gnupg package.