A TOCTOU race condition was found in the way the systemd-logind login manager of the systemd, a system and service manager for Linux, performed removal of particular records related with user session upon user logout. A local attacker could use this flaw to conduct symbolic link attacks, potentially leading to removal of arbitrary system file.
Created attachment 570001 [details] Proposed patch from Michal Schmidt, original issue reporter
This issue affects the versions of the systemd package, as shipped with Fedora release of 15 and 16.
The preliminary embargo date for this issue has been set up to this Friday, 2012-03-16.
The CVE identifier of CVE-2012-1174 has been assigned to this issue.
(In reply to comment #3) > This issue affects the versions of the systemd package, as shipped with Fedora > release of 15 and 16. Just a note: The above sentence is correct, even though F15 does not contain the systemd-logind daemon. In F15 the vulnerable code is called from the PAM module instead. I haven't tried exploiting it on F15, but I see nothing that would make it impossible.
Created systemd tracking bugs for this issue Affects: fedora-all [bug 804118]
Upstream patch: [1] http://cgit.freedesktop.org/systemd/systemd/commit/?id=5ebff5337594d690b322078c512eb222d34aaa82
systemd-26-18.fc15 has been pushed to the Fedora 15 stable repository. If problems still persist, please make note of it in this bug report.
systemd-37-17.fc16 has been pushed to the Fedora 16 stable repository. If problems still persist, please make note of it in this bug report.
systemd-44-6.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.