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.

The remote host is running a version of Openfire that is affected by an identity spoofing vulnerability. 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.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2025-59154)

ID	Name	Product	Family	Severity
265328	Openfire < 5.0.2 / 5.1.0 Identity Spoofing	Nessus	CGI abuses	medium
435333	SCA: security update for org.igniterealtime.openfire:xmppserver (GHSA-w252-645g-87mp)	Tenable Cloud Security	SCA Checks	medium
435333	SCA: security update for org.igniterealtime.openfire:xmppserver (GHSA-w252-645g-87mp)	Tenable Self-Hosted Container Security	SCA Checks	medium

Detections

Analytics

CVE-2025-59154

medium

Tenable Plugins

medium

medium

medium