linux-pam (aka Linux PAM) before 1.6.0 allows attackers to cause a denial of service (blocked login process) via mkfifo because the openat call (for protect_dir) lacks O_DIRECTORY.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Linux-pam | Linux-pam | * | 1.6.0 (excluding) |
| Red Hat Enterprise Linux 8 | RedHat | pam-0:1.3.1-33.el8 | * |
| Red Hat Enterprise Linux 9 | RedHat | pam-0:1.5.1-19.el9 | * |
| Red Hat Enterprise Linux 9 | RedHat | pam-0:1.5.1-19.el9 | * |
| Pam | Ubuntu | bionic | * |
| Pam | Ubuntu | devel | * |
| Pam | Ubuntu | esm-infra-legacy/trusty | * |
| Pam | Ubuntu | esm-infra/bionic | * |
| Pam | Ubuntu | esm-infra/focal | * |
| Pam | Ubuntu | esm-infra/xenial | * |
| Pam | Ubuntu | focal | * |
| Pam | Ubuntu | jammy | * |
| Pam | Ubuntu | lunar | * |
| Pam | Ubuntu | mantic | * |
| Pam | Ubuntu | trusty | * |
| Pam | Ubuntu | trusty/esm | * |
| Pam | Ubuntu | xenial | * |
References
- http://www.openwall.com/lists/oss-security/2024/01/18/3
- https://github.com/linux-pam/linux-pam
- https://github.com/linux-pam/linux-pam/commit/031bb5a5d0d950253b68138b498dc93be69a64cb
- https://github.com/linux-pam/linux-pam/releases/tag/v1.6.0
- http://www.openwall.com/lists/oss-security/2024/01/18/3
- https://github.com/linux-pam/linux-pam
- https://github.com/linux-pam/linux-pam/commit/031bb5a5d0d950253b68138b498dc93be69a64cb
- https://github.com/linux-pam/linux-pam/releases/tag/v1.6.0
- https://lists.debian.org/debian-lts-announce/2025/09/msg00021.html