CVE-2020-9495

Vulnerability

Analysis

CVE-2020-9495 is an LDAP injection vulnerability in the Apache Archiva login service, affecting all versions before 2.2.5 [1][2]. The root cause lies in insufficient sanitization of user-supplied input during LDAP authentication. By crafting special characters (such as LDAP filter wildcards or logical operators) in the login form, an attacker can manipulate the LDAP query used to look up user objects in the connected directory server [3].

Exploitation

Method

The attacker does not need prior authentication but must have network access to an Archiva instance configured with LDAP authentication. The exploitation technique relies on timing-based inference: by injecting characters that modify the LDAP filter and observing the response time of login requests, an attacker can guess the value of arbitrary attributes of LDAP user objects [3]. For example, injecting conditions that cause the LDAP search to return or not return results will lead to measurable differences in response latency.

Impact

Successful exploitation allows an attacker to extract sensitive attribute data from LDAP user objects—such as email addresses, group memberships, or other directory information—without legitimate credentials [1][3]. This information leakage could aid further targeted attacks, such as privilege escalation or social engineering. The vulnerability does not directly allow authentication bypass or remote code execution.

Mitigation

The issue is fixed in Apache Archiva 2.2.5 [1][2]. Users are strongly advised to upgrade to this version or later. There are no known workarounds, and the vulnerability is only present when LDAP authentication is enabled. The Apache Software Foundation has not reported active exploitation in the wild as of the publication date.