CVE-2020-1957: 
Apache Shiro vulnerability analysis and mitigation

CVE-2020-1957 is a security vulnerability discovered in Apache Shiro versions before 1.5.2. The vulnerability affects installations where Apache Shiro is used with Spring dynamic controllers, where a specially crafted request could lead to an authentication bypass (NVD, CVE). The vulnerability was disclosed on March 25, 2020, and was assigned a CVSS v3.1 base score of 9.8 (CRITICAL).

The vulnerability received a CVSS v3.1 base score of 9.8 (CRITICAL) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating network accessibility, low attack complexity, no privileges required, and no user interaction needed. The vulnerability also received a CVSS v2.0 base score of 7.5 (HIGH) with the vector (AV:N/AC:L/Au:N/C:P/I:P/A:P) (NVD).

When successfully exploited, this vulnerability allows attackers to bypass authentication mechanisms in Apache Shiro when used with Spring dynamic controllers. This could potentially lead to unauthorized access to protected resources and compromise of system security (NVD).

The primary mitigation is to upgrade Apache Shiro to version 1.5.2 or later. Various distributions have also released security updates, including Debian which released version 1.2.3-1+deb8u1 for Jessie (Debian Advisory).

The vulnerability prompted immediate response from various Apache projects, with Apache Camel quickly updating to Shiro 1.5.2 to address the vulnerability. Geode users expressed concerns about the critical security vulnerability in shiro-1.4.1.jar (Geode List).