Description
fs/open.c in the Linux kernel before 2.6.22 does not properly strip setuid and setgid bits when there is a write to a file, which allows local users to gain the privileges of a different group, and obtain sensitive information or possibly have unspecified other impact, by creating an executable file in a setgid directory through the (1) truncate or (2) ftruncate function in conjunction with memory-mapped I/O.
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 4.0 | fai-kernels | 1.17+etch.22etch3 | DSA-1653-1 |
| Debian 4.0 | linux-2.6 | 2.6.18.dfsg.1-22etch3 | DSA-1653-1 |
| Debian 4.0 | user-mode-linux | 2.6.18-1um-2etch.22etch3 | DSA-1653-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | kernel +12 | 2.6.18-92.1.18.el5 | RHSA-2008:0957 |
| RHEL 4 | kernel +10 | 2.6.9-78.0.8.EL | RHSA-2008:0972 |
| RHEL 3 | kernel +8 | 2.4.21-58.EL | RHSA-2008:0973 |
| RHEL 2 | kernel +8 | 2.4.9-e.74 | RHSA-2009:0001, RHSA-2008:0787 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Exploit-DB 1
- Linux Kernel < 2.6.22 - 'ftruncate()'/'open()' Local Privilege Escalation EDB-6851 · local · Oct 27, 2008 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 6
- RHSA-2008:0957 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- RHSA-2009:0001 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2008:0972 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- RHSA-2008:0973 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-1653-1 fai-kernels linux-2.6 user-mode-linux - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- RHSA-2008:0787 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
References
- http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.22
- 32485 third-party-advisory
- 31368 vdb-entry
- http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.26.y.git%3Ba=commit%3Bh=7b82dc0e64e93f430182f36b46b79fcee87d3532
- 32237 third-party-advisory
- RHSA-2008:0957 vendor-advisory
- RHSA-2008:0972 vendor-advisory
- [oss-security] 20080924 Re: CVE request: kernel: open() call allows setgid bit when user is not in new file's group mailing-list
- SUSE-SA:2008:056 vendor-advisory
- oval:org.mitre.oval:def:6386 vdb-entry signature
- 33280 third-party-advisory
- DSA-1653 vendor-advisory
- [oss-security] 20080924 CVE request: kernel: open() call allows setgid bit when user is not in new file's group mailing-list
- 32356 third-party-advisory
- 32918 third-party-advisory
- USN-679-1 vendor-advisory
- oval:org.mitre.oval:def:9511 vdb-entry signature
- 32759 third-party-advisory
- MDVSA-2008:220 vendor-advisory
- 32344 third-party-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=463661
- http://bugzilla.kernel.org/show_bug.cgi?id=8420
- http://kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.22
- RHSA-2008:0973 vendor-advisory
- RHSA-2008:0787 vendor-advisory
- SUSE-SA:2008:051 vendor-advisory
- 32799 third-party-advisory
- linux-kernel-open-privilege-escalation(45539) vdb-entry
- SUSE-SA:2008:057 vendor-advisory
- SUSE-SR:2008:025 vendor-advisory
- 33201 third-party-advisory