Description
The check_acl function in pam_xauth.c in the pam_xauth module in Linux-PAM (aka pam) 1.1.2 and earlier does not verify that a certain ACL file is a regular file, which might allow local users to cause a denial of service (resource consumption) via a special file.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | pam | 1.1.3-1 | — |
| Debian 13 | pam | 1.1.3-1 | — |
| Debian 12 | pam | 1.1.3-1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | pam +1 | 1.1.1-4.el6_0.1 | RHSA-2010:0891 |
| RHEL 5 | pam +1 | 0.99.6.2-6.el5_5.2 | RHSA-2010:0819 |
Advisories 2
- RHSA-2010:0819 Red Hat Security Advisory: pam security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2010:0891 Red Hat Security Advisory: pam security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
References
- linuxpam-checkacl-dos(65036) vdb-entry
- GLSA-201206-31 vendor-advisory
- [oss-security] 20101004 Re: Minor security flaw with pam_xauth mailing-list
- http://git.altlinux.org/people/ldv/packages/?p=pam.git%3Ba=commit%3Bh=Linux-PAM-1_1_2-2-gffe7058c70253d574b1963c7c93002bd410fddc9
- 46045 vdb-entry
- 49711 third-party-advisory