ALAS-2021-1493

Related Vulnerabilities: CVE-2020-9484   CVE-2021-25329  

A deserialization flaw was discovered in Apache Tomcat's use of a FileStore. Under specific circumstances, an attacker can use a specially crafted request to trigger Remote Code Execution through deserialization of the file under their control. The highest threat from the vulnerability is to data confidentiality and integrity as well as system availability. (CVE-2020-9484) The fix for CVE-2020-9484 was incomplete. When using Apache Tomcat 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41, 8.5.0 to 8.5.61 or 7.0.0. to 7.0.107 with a configuration edge case that was highly unlikely to be used, the Tomcat instance was still vulnerable to CVE-2020-9494. Note that both the previously published prerequisites for CVE-2020-9484 and the previously published mitigations for CVE-2020-9484 also apply to this issue. (CVE-2021-25329)

ALAS-2021-1493


Amazon Linux AMI Security Advisory: ALAS-2021-1493
Advisory Release Date: 2021-04-07 00:18 Pacific
Advisory Updated Date: 2021-04-07 18:50 Pacific
Severity: Low

Issue Overview:

A deserialization flaw was discovered in Apache Tomcat's use of a FileStore. Under specific circumstances, an attacker can use a specially crafted request to trigger Remote Code Execution through deserialization of the file under their control. The highest threat from the vulnerability is to data confidentiality and integrity as well as system availability. (CVE-2020-9484)

The fix for CVE-2020-9484 was incomplete. When using Apache Tomcat 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41, 8.5.0 to 8.5.61 or 7.0.0. to 7.0.107 with a configuration edge case that was highly unlikely to be used, the Tomcat instance was still vulnerable to CVE-2020-9494. Note that both the previously published prerequisites for CVE-2020-9484 and the previously published mitigations for CVE-2020-9484 also apply to this issue. (CVE-2021-25329)


Affected Packages:

tomcat7


Issue Correction:
Run yum update tomcat7 to update your system.

New Packages:
noarch:
    tomcat7-webapps-7.0.108-1.40.amzn1.noarch
    tomcat7-log4j-7.0.108-1.40.amzn1.noarch
    tomcat7-el-2.2-api-7.0.108-1.40.amzn1.noarch
    tomcat7-javadoc-7.0.108-1.40.amzn1.noarch
    tomcat7-lib-7.0.108-1.40.amzn1.noarch
    tomcat7-admin-webapps-7.0.108-1.40.amzn1.noarch
    tomcat7-7.0.108-1.40.amzn1.noarch
    tomcat7-servlet-3.0-api-7.0.108-1.40.amzn1.noarch
    tomcat7-jsp-2.2-api-7.0.108-1.40.amzn1.noarch
    tomcat7-docs-webapp-7.0.108-1.40.amzn1.noarch

src:
    tomcat7-7.0.108-1.40.amzn1.src