CVE-2020-2170: Jenkins Security Advisory 2020-03-25

This advisory announces vulnerabilities in the following Jenkins deliverables:

• Jenkins (core)
• Artifactory Plugin
• Azure Container Service Plugin
• OpenShift Pipeline Plugin
• Pipeline: AWS Steps Plugin
• Queue cleanup Plugin
• RapidDeploy Plugin

Descriptions****CSRF protection for any URL could be bypassed

SECURITY-1774 / CVE-2020-2160
Severity (CVSS): High
Description:

An extension point in Jenkins allows selectively disabling cross-site request forgery (CSRF) protection for specific URLs.

Implementations of that extension point received a different representation of the URL path than the Stapler web framework uses to dispatch requests in Jenkins 2.227 and earlier, LTS 2.204.5 and earlier. This discrepancy allowed attackers to craft URLs that would bypass the CSRF protection of any target URL.

Jenkins now uses the same representation of the URL path to decide whether CSRF protection is needed for a given URL as the Stapler web framework uses.

In case of problems, administrators can disable this security fix by setting the system property hudson.security.csrf.CrumbFilter.UNPROCESSED_PATHINFO to true.

As an additional safeguard, semicolon (;) characters in the path part of a URL are now banned by default. Administrators can disable this protection by setting the system property jenkins.security.SuspiciousRequestFilter.allowSemicolonsInPath to true.

Stored XSS vulnerability in label expression validation

SECURITY-1781 / CVE-2020-2161
Severity (CVSS): Medium
Description:

Users with Agent/Configure permissions can define labels for nodes. These labels can be referenced in job configurations to restrict where a job can be run.

In Jenkins 2.227 and earlier, LTS 2.204.5 and earlier, the form validation for label expressions in job configuration forms did not properly escape label names, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by users able to define node labels.

Jenkins now correctly escapes node labels that are shown in form validation on job configuration pages.

Stored XSS vulnerability in file parameters

SECURITY-1793 / CVE-2020-2162
Severity (CVSS): Medium
Description:

Jenkins 2.227 and earlier, LTS 2.204.5 and earlier served files uploaded as file parameters to a build without specifying appropriate Content-Security-Policy HTTP headers. This resulted in a stored cross-site scripting (XSS) vulnerability exploitable by users with permissions to build a job with file parameters.

Jenkins now sets Content-Security-Policy HTTP headers when serving files uploaded via a file parameter to the same value as used for files in workspaces and archived artifacts not served using the Resource Root URL.

The system property hudson.model.DirectoryBrowserSupport.CSP can be set to override the value of Content-Security-Policy headers sent when serving these files. This is the same system property used for files in workspaces and archived artifacts unless those are served via the Resource Root URL and works the same way for file parameters. See Configuring Content Security Policy to learn more.

Even when Jenkins is configured to serve files in workspaces and archived artifacts using the Resource Root URL (introduced in Jenkins 2.200), file parameters are not, and therefore still subject to Content-Security-Policy restrictions.

Stored XSS vulnerability in list view column headers

SECURITY-1796 / CVE-2020-2163
Severity (CVSS): Medium
Description:

Jenkins 2.227 and earlier, LTS 2.204.5 and earlier processed HTML embedded in list view column headers. This resulted in a stored cross-site scripting (XSS) vulnerability exploitable by users able to control the content of column headers.

The following plugins are known to allow users to define column headers:

• Warnings NG

• Maven Info

• Link Column

Further plugins may also allow users to define column headers.

Jenkins no longer processes HTML embedded in list view column headers.

Passwords stored in plain text by Artifactory Plugin

SECURITY-1542 (1) / CVE-2020-2164
Severity (CVSS): Low
Description:

Artifactory Plugin 3.5.0 and earlier stores its Artifactory server password in plain text in the global configuration file org.jfrog.hudson.ArtifactoryBuilder.xml. This password can be viewed by users with access to the Jenkins controller file system.

Artifactory Plugin 3.6.0 now stores the Artifactory server password encrypted. This change is effective once the global configuration is saved the next time.

Passwords transmitted in plain text by Artifactory Plugin

SECURITY-1542 (2) / CVE-2020-2165
Severity (CVSS): Low
Affected plugin: artifactory
Description:

Artifactory Plugin stores Artifactory server passwords in its global configuration file org.jfrog.hudson.ArtifactoryBuilder.xml on the Jenkins controller as part of its configuration.

While the password is stored encrypted on disk since Artifactory Plugin 3.6.0, it is transmitted in plain text as part of the configuration form by Artifactory Plugin 3.6.0 and earlier. This can result in exposure of the password through browser extensions, cross-site scripting vulnerabilities, and similar situations.

Artifactory Plugin 3.6.1 transmits the password in its global configuration encrypted.

RCE vulnerability in Pipeline: AWS Steps Plugin

SECURITY-1741 / CVE-2020-2166
Severity (CVSS): High
Affected plugin: pipeline-aws
Description:

Pipeline: AWS Steps Plugin 1.40 and earlier does not configure its YAML parser to prevent the instantiation of arbitrary types. This results in a remote code execution (RCE) vulnerability exploitable by users able to provide YAML input files to Pipeline: AWS Steps Plugin’s build steps.

Pipeline: AWS Steps Plugin 1.41 configures its YAML parser to only instantiate safe types.

RCE vulnerability in OpenShift Pipeline Plugin

SECURITY-1739 / CVE-2020-2167
Severity (CVSS): High
Affected plugin: openshift-pipeline
Description:

OpenShift Pipeline Plugin 1.0.56 and earlier does not configure its YAML parser to prevent the instantiation of arbitrary types. This results in a remote code execution (RCE) vulnerability exploitable by users able to provide YAML input files to OpenShift Pipeline Plugin’s build step.

OpenShift Pipeline Plugin 1.0.57 configures its YAML parser to only instantiate safe types.

RCE vulnerability in Azure Container Service Plugin

SECURITY-1732 / CVE-2020-2168
Severity (CVSS): High
Affected plugin: azure-acs
Description:

Azure Container Service Plugin 1.0.1 and earlier does not configure its YAML parser to prevent the instantiation of arbitrary types. This results in a remote code execution (RCE) vulnerability exploitable by users able to provide YAML input files to Azure Container Service Plugin’s build step.

Azure Container Service Plugin 1.0.2 configures its YAML parser to only instantiate safe types.

Reflected XSS vulnerability in Queue cleanup Plugin

SECURITY-1724 / CVE-2020-2169
Severity (CVSS): Medium
Affected plugin: queue-cleanup
Description:

A form validation HTTP endpoint in Queue cleanup Plugin 1.3 and earlier does not escape a query parameter displayed in an error message. This results in a reflected cross-site scripting vulnerability (XSS).

Queue cleanup Plugin 1.4 correctly escapes the query parameter.

Stored XSS vulnerability in RapidDeploy Plugin

SECURITY-1676 / CVE-2020-2170
Severity (CVSS): Medium
Affected plugin: rapiddeploy-jenkins
Description:

RapidDeploy Plugin 4.2 and earlier does not escape package names in its displayed table of packages obtained from a remote server. This results in a stored cross-site scripting (XSS) vulnerability exploitable by users able to configure jobs.

RapidDeploy Plugin 4.2.1 escapes package names.

XXE vulnerability in RapidDeploy Plugin

SECURITY-1677 / CVE-2020-2171
Severity (CVSS): High
Affected plugin: rapiddeploy-jenkins
Description:

RapidDeploy Plugin 4.2 and earlier does not configure its XML parser to prevent XML external entity (XXE) attacks.

This allows a user able to control the input files for the ‘RapidDeploy deployment package build’ build or post-build step to have Jenkins parse a crafted file that uses external entities for extraction of secrets from the Jenkins controller, server-side request forgery, or denial-of-service attacks.

RapidDeploy Plugin 4.2.1 disables external entity resolution for its XML parser.

Severity

• SECURITY-1542 (1): Low
• SECURITY-1542 (2): Low
• SECURITY-1676: Medium
• SECURITY-1677: High
• SECURITY-1724: Medium
• SECURITY-1732: High
• SECURITY-1739: High
• SECURITY-1741: High
• SECURITY-1774: High
• SECURITY-1781: Medium
• SECURITY-1793: Medium
• SECURITY-1796: Medium

Affected Versions

• Jenkins weekly up to and including 2.227
• Jenkins LTS up to and including 2.204.5
• Artifactory Plugin up to and including 3.6.0
• Azure Container Service Plugin up to and including 1.0.1
• OpenShift Pipeline Plugin up to and including 1.0.56
• Pipeline: AWS Steps Plugin up to and including 1.40
• Queue cleanup Plugin up to and including 1.3
• RapidDeploy Plugin up to and including 4.2

Fix

• Jenkins weekly should be updated to version 2.228
• Jenkins LTS should be updated to version 2.204.6 or 2.222.1
• Artifactory Plugin should be updated to version 3.6.1
• Azure Container Service Plugin should be updated to version 1.0.2
• OpenShift Pipeline Plugin should be updated to version 1.0.57
• Pipeline: AWS Steps Plugin should be updated to version 1.41
• Queue cleanup Plugin should be updated to version 1.4
• RapidDeploy Plugin should be updated to version 4.2.1

These versions include fixes to the vulnerabilities described above. All prior versions are considered to be affected by these vulnerabilities unless otherwise indicated.

Credit

The Jenkins project would like to thank the reporters for discovering and reporting these vulnerabilities:

• Daniel Beck, CloudBees, Inc. for SECURITY-1676, SECURITY-1677
• Daniel Kalinowski of ISEC.pl Research Team for SECURITY-1732
• James Holderness, IB Boost, and independently, ethorsa for SECURITY-1542 (1)
• Nick Collisson from Gemini Trust Company, LLC. for SECURITY-1774
• Phu X. Mai, University of Luxembourg for SECURITY-1793
• Wadeck Follonier, CloudBees, Inc. for SECURITY-1724, SECURITY-1781