CVE-2023-50981 — ModularSquareRoot in Crypto++ (aka cryptopp) through 8

ModularSquareRoot in Crypto++ (aka cryptopp) through 8.9.0 allows attackers to cause a denial of service (infinite loop) via crafted DER public-key data associated with squared odd numbers, such as the square of 268995137513890432434389773128616504853.

01What is this vulnerability?

ModularSquareRoot in Crypto++ (aka cryptopp) through 8.9.0 allows attackers to cause a denial of service (infinite loop) via crafted DER public-key data associated with squared odd numbers, such as the square of 268995137513890432434389773128616504853.

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: 2023-12-18T00:00:00.000Z
• Last modified: 2025-05-07T20:40:09.701Z

09References

• github.com — https://github.com/weidai11/cryptopp/issues/1249