#VU92788 Integer overflow in Linux kernel - CVE-2018-12896
Vulnerability identifier: #VU92788
Vulnerability risk: Low
CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID:
CWE-ID:
CWE-190
Exploitation vector: Local
Exploit availability: No
Vulnerable software:
Linux kernel
Operating systems & Components /
Operating system
Vendor: Linux Foundation
Description
The vulnerability allows a local user to perform a denial of service (DoS) attack.
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.
Mitigation
Install update from vendor's repository.
Vulnerable software versions
Linux kernel: All versions
External links
https://bugzilla.kernel.org/show_bug.cgi?id=200189
https://github.com/lcytxw/bug_repro/tree/master/bug_200189
https://github.com/torvalds/linux/commit/78c9c4dfbf8c04883941445a195276bb4bb92c76
https://lists.debian.org/debian-lts-announce/2019/03/msg00017.html
https://lists.debian.org/debian-lts-announce/2019/03/msg00034.html
https://lists.debian.org/debian-lts-announce/2019/04/msg00004.html
https://usn.ubuntu.com/3847-1/
https://usn.ubuntu.com/3847-2/
https://usn.ubuntu.com/3847-3/
https://usn.ubuntu.com/3848-1/
https://usn.ubuntu.com/3848-2/
https://usn.ubuntu.com/3849-1/
https://usn.ubuntu.com/3849-2/
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
