OpenIdentityPlatform OpenDJ up to 5.1.1 SASL PlainSASLMechanismHandler.java improper authorization

Summaryinfo

A vulnerability was found in OpenIdentityPlatform OpenDJ up to 5.1.1. It has been declared as very critical. This affects an unknown function of the file opendj-server-legacy/src/main/java/org/opends/server/extensions/PlainSASLMechanismHandler.java of the component SASL. Such manipulation leads to improper authorization. This vulnerability is listed as CVE-2026-73644. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in OpenIdentityPlatform OpenDJ up to 5.1.1. Affected by this issue is some unknown processing of the file opendj-server-legacy/src/main/java/org/opends/server/extensions/PlainSASLMechanismHandler.java of the component SASL. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. CVE summarizes:

OpenDJ is an LDAPv3 compliant directory service. Prior to 5.1.2, the SASL PLAIN authorization identity path in opendj-server-legacy/src/main/java/org/opends/server/extensions/PlainSASLMechanismHandler.java checked the PROXIED_AUTH privilege but did not evaluate the mayProxy proxy ACI scope when an authzid resolved to a different user. Both dn: and u: or bare authzid forms could therefore let an authenticated account holding PROXIED_AUTH assume any resolvable non-root identity outside the identities permitted by its proxy ACI. The fix returns INVALID_CREDENTIALS (49) before password verification when the target authorization identity is not permitted. This issue is fixed in version 5.1.2.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-73644 since 08/13/2026. The exploitation is known to be easy. The attack may be launched remotely. Additional levels of successful authentication are necessary for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 08/13/2026). This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

Upgrading to version 5.1.2 eliminates this vulnerability.

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Productinfo

Type

• Directory Service Software

Vendor

• OpenIdentityPlatform

Name

• OpenDJ

Version

• 5.1.0
• 5.1.1

Website

• Product: https://github.com/OpenIdentityPlatform/OpenDJ/

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