Alerts This Week
Warning Icon 1 1,149
Alerts This Week
Warning Icon 1 1,149

Ubuntu 24.04: Denial of Service Due to PAM/U2F Auth Bypass USN-7806-1

ubuntu
Calendar Grey October 6, 2025
Dist Ubuntu Esm H88
PAM/U2F on Ubuntu can crash or run admin programs due to crafted files; important update available.
PAM/U2F could be made to crash or run programs as an administrator if it opened a specially crafted file.

Summary

PAM/U2F could be made to crash or run programs as an administrator if it

opened a specially crafted file.

Software Description:

- pam-u2f: A module that implements PAM over U2F and FIDO2

Details:

It was discovered that PAM/U2F could allow for authentication bypass in

some configurations. An attacker could possibly use this issue to execute

arbitrary code or cause a denial of service.

Topics%20covered

Topics Covered

security advisory critical DoS Ubuntu authentication bypass pam-u2f

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 24.04 LTS
  libpam-u2f                      1.1.0-1.1+deb12u1build0.24.04.1
  pamu2fcfg                       1.1.0-1.1+deb12u1build0.24.04.1

Ubuntu 22.04 LTS
  libpam-u2f                      1.1.0-1.1+deb12u1build0.22.04.1
  pamu2fcfg                       1.1.0-1.1+deb12u1build0.22.04.1

Ubuntu 20.04 LTS
  libpam-u2f                      1.0.8-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro
  pamu2fcfg                       1.0.8-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro

In general, a standard system update will make all the necessary changes.

References

https://ubuntu.com/security/notices/USN-7806-1

CVE-2025-23013

Severity
critical
Lowest
Low
Medium
High
Critical

Ubuntu Security Notice USN-7806-1

Topics%20covered

Topics Covered

security advisory critical DoS Ubuntu authentication bypass pam-u2f

Package Information

Get the latest News and Insights

Get the latest Linux and open source security news straight to your inbox.

Your message here