CVE-2019-17185 — In FreeRADIUS 3

In FreeRADIUS 3.0.x before 3.0.20, the EAP-pwd module used a global OpenSSL BN_CTX instance to handle all handshakes. This mean multiple threads use the same BN_CTX instance concurrently, resulting in crashes when concurrent EAP-pwd handshakes are initiated. This can be abused by

01What is this vulnerability?

In FreeRADIUS 3.0.x before 3.0.20, the EAP-pwd module used a global OpenSSL BN_CTX instance to handle all handshakes. This mean multiple threads use the same BN_CTX instance concurrently, resulting in crashes when concurrent EAP-pwd handshakes are initiated. This can be abused by an adversary as a Denial-of-Service (DoS) attack.

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: 2020-03-21T00:13:05.000Z
• Last modified: 2024-08-05T01:33:17.262Z

09References

• freeradius.org — https://freeradius.org/security/
• github.com — https://github.com/FreeRADIUS/freeradius-server/releases/tag/release_3_0_20
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00039.html