Arch Linux Security Advisory ASA-202007-6

Severity: High
Date : 2020-07-31
CVE-ID : CVE-2020-10759
Package : libjcat
Type : insufficient validation
Remote : Yes
Link : https://security.archlinux.org/AVG-1185

Summary

The package libjcat before version 0.1.3-1 is vulnerable to
insufficient validation.

Resolution

Upgrade to 0.1.3-1.

pacman -Syu “libjcat>=0.1.3-1”

The problem has been fixed upstream in version 0.1.3.

Workaround

None.

Description

A PGP signature verification bypass has been found in fwupd prior to
1.4.0, and in libjcat <= 0.1.2. The issue is that if a detached
signature is actually a PGP message, gpgme_op_verify() returns the
rather perplexing GPG_ERR_NO_ERROR, and then gpgme_op_verify_result()
builds an empty list.

Impact

A local attacker could pass signature validation with a crafted
message.

References

https://github.com/justinsteven/advisories/blob/master/2020_fwupd_dangling_s3_bucket_and_CVE-2020-10759_signature_verification_bypass.md
https://github.com/hughsie/libjcat/commit/839b89f
https://security.archlinux.org/CVE-2020-10759