Vulnerability Description
An issue was discovered in the Linux kernel through 4.17.3. An Integer Overflow in kernel/time/posix-timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically makes the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. For example, a local user can cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | <= 4.17.3 |
| Debian | Debian Linux | 8.0 |
| Canonical | Ubuntu Linux | 12.04 |
Related Weaknesses (CWE)
References
- https://bugzilla.kernel.org/show_bug.cgi?id=200189Issue TrackingVendor Advisory
- https://github.com/lcytxw/bug_repro/tree/master/bug_200189ExploitThird Party Advisory
- https://github.com/torvalds/linux/commit/78c9c4dfbf8c04883941445a195276bb4bb92c7PatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/03/msg00017.htmlMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/03/msg00034.htmlMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/04/msg00004.htmlMailing ListThird Party Advisory
- https://usn.ubuntu.com/3847-1/Third Party Advisory
- https://usn.ubuntu.com/3847-2/Third Party Advisory
- https://usn.ubuntu.com/3847-3/Third Party Advisory
- https://usn.ubuntu.com/3848-1/Third Party Advisory
- https://usn.ubuntu.com/3848-2/Third Party Advisory
- https://usn.ubuntu.com/3849-1/Third Party Advisory
- https://usn.ubuntu.com/3849-2/Third Party Advisory
- https://bugzilla.kernel.org/show_bug.cgi?id=200189Issue TrackingVendor Advisory
- https://github.com/lcytxw/bug_repro/tree/master/bug_200189ExploitThird Party Advisory
FAQ
What is CVE-2018-12896?
CVE-2018-12896 is a vulnerability with a CVSS score of 5.5 (MEDIUM). An issue was discovered in the Linux kernel through 4.17.3. An Integer Overflow in kernel/time/posix-timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on in...
How severe is CVE-2018-12896?
CVE-2018-12896 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2018-12896?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel, Debian Debian Linux, Canonical Ubuntu Linux.