CVE-2023-52389 — UTF32Encoding

UTF32Encoding.cpp in POCO has a Poco::UTF32Encoding integer overflow and resultant stack buffer overflow because Poco::UTF32Encoding::convert() and Poco::UTF32::queryConvert() may return a negative integer if a UTF-32 byte sequence evaluates to a value of 0x80000000 or higher. Th

01What is this vulnerability?

UTF32Encoding.cpp in POCO has a Poco::UTF32Encoding integer overflow and resultant stack buffer overflow because Poco::UTF32Encoding::convert() and Poco::UTF32::queryConvert() may return a negative integer if a UTF-32 byte sequence evaluates to a value of 0x80000000 or higher. This is fixed in 1.11.8p2, 1.12.5p2, and 1.13.0.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2024-01-27T00:00:00.000Z
• Last modified: 2025-05-29T15:11:56.786Z

09References

• pocoproject.org — https://pocoproject.org/blog/?p=1226
• github.com — https://github.com/pocoproject/poco/issues/4320
• github.com — https://github.com/pocoproject/poco/compare/poco-1.12.5p2-release...poco-1.13.0-…