Vulnerability in Igniterealtime Openfire

CVE-2025-59154

Openfire is an XMPP server licensed under the Open Source Apache License. Openfire’s SASL EXTERNAL mechanism for client TLS authentication contains a vulnerability in how it extracts user identities from X.509 certificates. Instead of parsing the structured ASN.1 data, the code calls X509Certificate.getSubjectDN().getName() and applies a regex to look for CN=. This method produces a provider-dependent string that does not escape special characters. In SunJSSE (sun.security.x509.X500Name), for example, commas and equals signs inside attribute values are not escaped. As a result, a malicious certificate can embed CN= inside another attribute value (e.g. OU="CN=admin,"). The regex will incorrectly interpret this as a legitimate Common Name and extract admin. If SASL EXTERNAL is enabled and configured to map CNs to user accounts, this allows the attacker to impersonate another user. The fix is included in Openfire 5.0.2 and 5.1.0.

EPSS: 0.002 (12.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-59154?
CVE-2025-59154 is a medium-severity vulnerability in Igniterealtime Openfire, classified under Authentication Bypass by Spoofing. CVSS score: 5.9/10. Published 2025-09-15.
How severe is CVE-2025-59154?
Medium severity. CVSS v3 base score is 5.9 out of 10.