CVE-2020-11989

Vulnerability

Overview

CVE-2020-11989 is an authentication bypass vulnerability in Apache Shiro versions prior to 1.5.3. The flaw occurs when Shiro is used in conjunction with Spring dynamic controllers. A specially crafted HTTP request can cause Shiro to incorrectly evaluate authentication checks, allowing an attacker to bypass security controls [1].

Exploitation

To exploit this vulnerability, the target application must be using Apache Shiro with Spring dynamic controllers. The attacker does not need prior authentication; they only need network access to send a malicious request. The crafted request manipulates the request path or parameters in a way that Shiro fails to properly match against its security rules, thereby skipping authentication [1].

Impact

Successful exploitation allows an attacker to bypass authentication entirely. This can lead to unauthorized access to protected resources, including administrative interfaces, sensitive data, or functionality that should require authentication. The impact is high as it undermines the core security mechanism of the application [1].

Mitigation

The vulnerability is fixed in Apache Shiro version 1.5.3. Users should upgrade to this version or later. No workarounds are documented; upgrading is the recommended action [1].