CVE-2018-12896: canonical ubuntu_linux Integer Overflow or Wraparound

Vulnerability summary

CVE-2018-12896 is a medium (CVSS 5.5) Integer Overflow or Wraparound vulnerability in canonical ubuntu_linux. EPSS estimates a 0.64% chance of exploitation in the next 30 days, higher than 50.6% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 02-07-2018
   PublishedVulnerability first disclosed.
2. 05-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.