ALAS-2016-764

Related Vulnerabilities: CVE-2016-0762   CVE-2016-5018   CVE-2016-6325   CVE-2016-6794   CVE-2016-6796   CVE-2016-6797  

It was discovered that the Tomcat packages installed certain configuration files read by the Tomcat initialization script as writeable to the tomcat group. A member of the group or a malicious web application deployed on Tomcat could use this flaw to escalate their privileges. (CVE-2016-6325) A malicious web application was able to bypass a configured SecurityManager via a Tomcat utility method that was accessible to web applications. (CVE-2016-5018) The Realm implementations did not process the supplied password if the supplied user name did not exist. This made a timing attack possible to determine valid user names. Note that the default configuration includes the LockOutRealm which makes exploitation of this vulnerability harder. (CVE-2016-0762) When a SecurityManager is configured, a web application's ability to read system properties should be controlled by the SecurityManager. Tomcat's system property replacement feature for configuration files could be used by a malicious web application to bypass the SecurityManager and read system properties that should not be visible. (CVE-2016-6794) A malicious web application was able to bypass a configured SecurityManager via manipulation of the configuration parameters for the JSP Servlet. (CVE-2016-6796) The ResourceLinkFactory did not limit web application access to global JNDI resources to those resources explicitly linked to the web application. Therefore, it was possible for a web application to access any global JNDI resource whether an explicit ResourceLink had been configured or not. (CVE-2016-6797)

ALAS-2016-764


Amazon Linux AMI Security Advisory: ALAS-2016-764
Advisory Release Date: 2016-11-10 18:00 Pacific
Advisory Updated Date: 2016-11-10 18:00 Pacific
Severity: Important

Issue Overview:

It was discovered that the Tomcat packages installed certain configuration files read by the Tomcat initialization script as writeable to the tomcat group. A member of the group or a malicious web application deployed on Tomcat could use this flaw to escalate their privileges. (CVE-2016-6325)

A malicious web application was able to bypass a configured SecurityManager via a Tomcat utility method that was accessible to web applications. (CVE-2016-5018)

The Realm implementations did not process the supplied password if the supplied user name did not exist. This made a timing attack possible to determine valid user names. Note that the default configuration includes the LockOutRealm which makes exploitation of this vulnerability harder. (CVE-2016-0762)

When a SecurityManager is configured, a web application's ability to read system properties should be controlled by the SecurityManager. Tomcat's system property replacement feature for configuration files could be used by a malicious web application to bypass the SecurityManager and read system properties that should not be visible. (CVE-2016-6794)

A malicious web application was able to bypass a configured SecurityManager via manipulation of the configuration parameters for the JSP Servlet. (CVE-2016-6796)

The ResourceLinkFactory did not limit web application access to global JNDI resources to those resources explicitly linked to the web application. Therefore, it was possible for a web application to access any global JNDI resource whether an explicit ResourceLink had been configured or not. (CVE-2016-6797)


Affected Packages:

tomcat6, tomcat7, tomcat8


Issue Correction:
Run yum update tomcat6 to update your system.
Run yum update tomcat7 to update your system.
Run yum update tomcat8 to update your system.

New Packages:
noarch:
    tomcat6-webapps-6.0.47-1.7.amzn1.noarch
    tomcat6-servlet-2.5-api-6.0.47-1.7.amzn1.noarch
    tomcat6-jsp-2.1-api-6.0.47-1.7.amzn1.noarch
    tomcat6-javadoc-6.0.47-1.7.amzn1.noarch
    tomcat6-docs-webapp-6.0.47-1.7.amzn1.noarch
    tomcat6-el-2.1-api-6.0.47-1.7.amzn1.noarch
    tomcat6-6.0.47-1.7.amzn1.noarch
    tomcat6-admin-webapps-6.0.47-1.7.amzn1.noarch
    tomcat6-lib-6.0.47-1.7.amzn1.noarch
    tomcat7-el-2.2-api-7.0.72-1.21.amzn1.noarch
    tomcat7-7.0.72-1.21.amzn1.noarch
    tomcat7-admin-webapps-7.0.72-1.21.amzn1.noarch
    tomcat7-log4j-7.0.72-1.21.amzn1.noarch
    tomcat7-javadoc-7.0.72-1.21.amzn1.noarch
    tomcat7-docs-webapp-7.0.72-1.21.amzn1.noarch
    tomcat7-jsp-2.2-api-7.0.72-1.21.amzn1.noarch
    tomcat7-lib-7.0.72-1.21.amzn1.noarch
    tomcat7-webapps-7.0.72-1.21.amzn1.noarch
    tomcat7-servlet-3.0-api-7.0.72-1.21.amzn1.noarch
    tomcat8-el-3.0-api-8.0.38-1.65.amzn1.noarch
    tomcat8-admin-webapps-8.0.38-1.65.amzn1.noarch
    tomcat8-log4j-8.0.38-1.65.amzn1.noarch
    tomcat8-lib-8.0.38-1.65.amzn1.noarch
    tomcat8-8.0.38-1.65.amzn1.noarch
    tomcat8-servlet-3.1-api-8.0.38-1.65.amzn1.noarch
    tomcat8-jsp-2.3-api-8.0.38-1.65.amzn1.noarch
    tomcat8-docs-webapp-8.0.38-1.65.amzn1.noarch
    tomcat8-webapps-8.0.38-1.65.amzn1.noarch
    tomcat8-javadoc-8.0.38-1.65.amzn1.noarch

src:
    tomcat6-6.0.47-1.7.amzn1.src
    tomcat7-7.0.72-1.21.amzn1.src
    tomcat8-8.0.38-1.65.amzn1.src