ALAS-2020-1390

Related Vulnerabilities: CVE-2020-9484  

When using Apache Tomcat versions 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54 and 7.0.0 to 7.0.103 if a) an attacker is able to control the contents and name of a file on the server; and b) the server is configured to use the PersistenceManager with a FileStore; and c) the PersistenceManager is configured with sessionAttributeValueClassNameFilter="null" (the default unless a SecurityManager is used) or a sufficiently lax filter to allow the attacker provided object to be deserialized; and d) the attacker knows the relative file path from the storage location used by FileStore to the file the attacker has control over; then, using a specifically crafted request, the attacker will be able to trigger remote code execution via deserialization of the file under their control. Note that all of conditions a) to d) must be true for the attack to succeed. (CVE-2020-9484)

ALAS-2020-1390


Amazon Linux AMI Security Advisory: ALAS-2020-1390
Advisory Release Date: 2020-06-23 06:47 Pacific
Advisory Updated Date: 2020-06-26 04:57 Pacific
Severity: Important
References: CVE-2020-9484 

Issue Overview:

When using Apache Tomcat versions 10.0.0-M1 to 10.0.0-M4, 9.0.0.M1 to 9.0.34, 8.5.0 to 8.5.54 and 7.0.0 to 7.0.103 if a) an attacker is able to control the contents and name of a file on the server; and b) the server is configured to use the PersistenceManager with a FileStore; and c) the PersistenceManager is configured with sessionAttributeValueClassNameFilter="null" (the default unless a SecurityManager is used) or a sufficiently lax filter to allow the attacker provided object to be deserialized; and d) the attacker knows the relative file path from the storage location used by FileStore to the file the attacker has control over; then, using a specifically crafted request, the attacker will be able to trigger remote code execution via deserialization of the file under their control. Note that all of conditions a) to d) must be true for the attack to succeed. (CVE-2020-9484)


Affected Packages:

tomcat8


Issue Correction:
Run yum update tomcat8 to update your system.

New Packages:
noarch:
    tomcat8-8.5.56-1.84.amzn1.noarch
    tomcat8-docs-webapp-8.5.56-1.84.amzn1.noarch
    tomcat8-webapps-8.5.56-1.84.amzn1.noarch
    tomcat8-log4j-8.5.56-1.84.amzn1.noarch
    tomcat8-lib-8.5.56-1.84.amzn1.noarch
    tomcat8-el-3.0-api-8.5.56-1.84.amzn1.noarch
    tomcat8-servlet-3.1-api-8.5.56-1.84.amzn1.noarch
    tomcat8-javadoc-8.5.56-1.84.amzn1.noarch
    tomcat8-admin-webapps-8.5.56-1.84.amzn1.noarch
    tomcat8-jsp-2.3-api-8.5.56-1.84.amzn1.noarch

src:
    tomcat8-8.5.56-1.84.amzn1.src