CVE-2026-73644: OpenDJ: Authorization bypass in SASL PLAIN allowing a `proxied-auth` holder to impersonate any resolvable non-root user without an ACI proxy grant

Description

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Attack vector

Network

Complexity

Low

Privileges

Low

User interaction

None

Confidentiality

High

Integrity

High

Availability

None

Scope

Changed

Exploitation

Is it being used?

Exploit prediction (EPSS)0.4% · higher than 35% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

OP

OpenDJ · OpenIdentityPlatform

< 5.1.2 · source: vendor