Executive brief
Apache Shiro, a widely used security framework for Java applications, contains a vulnerability in its LDAP authentication component. An attacker can use specially crafted usernames to manipulate how the system identifies users during login. This could allow an unauthorized person to bypass security checks or log in as a different user, potentially gaining access to sensitive data or administrative functions.
Technical details
An LDAP injection vulnerability exists in Apache Shiro's DefaultLdapRealm class. The vulnerability is caused by the direct concatenation of user-supplied username input into the LDAP Distinguished Name (DN) template without proper escaping of RFC 2253 special characters. A remote, unauthenticated attacker can exploit this by providing a malicious username containing LDAP special characters to manipulate the DN structure used for LDAP bind authentication. Successful exploitation can result in authentication bypass or the ability to impersonate other users. The issue is fixed in Apache Shiro versions 2.2.1 and 3.0.0-alpha-2.
Affected products
- Apache Shiro <= 2.2.0, 3.0.0-alpha-1
Timeline
- 2026-06-17: disclosed
- 2026-06-17: advisory