CloudBees Security Advisory 2018-03-26

This advisory announces multiple vulnerabilities in Jenkins, CloudBees Jenkins Platform and CloudBees Jenkins Solutions.

 

SECURITY-261 and SECURITY-697 - GitHub Pull Request Builder Plugin stores GitHub access tokens in build.xml

GitHub Pull Request Builder Plugin stored serialized objects in build.xml files that contained the credential used to poll Jenkins. This can be used by users with master file system access to obtain GitHub credentials. Since 1.40.0, the plugin no longer stores serialized objects containing the credential on disk. Builds started before the plugin was updated to 1.40.0 will retain the encoded credentials on disk.We strongly recommend revoking old GitHub credentials used in Jenkins.

We’re providing a script for use in the Script Console that will attempt to remove old stored credentials from build.xml files.

SECURITY-262 - GitHub Pull Request Builder Plugin stores webhook secret in plain text

GitHub Pull Request Builder Plugin stored the webhook secret shared between Jenkins and GitHub in plain text. This allowed users with Jenkins master local file system access and Jenkins administrators to retrieve the stored password. The latter could result in exposure of the passwords through browser extensions, cross-site scripting vulnerabilities, and similar situations.

GitHub Pull Request Builder Plugin 1.32.1 and newer stores the webhook secret encrypted on disk.

SECURITY-308 - Cucumber Living Documentation Plugin disabled Content-Security-Policy for archived and workspace files

Jenkins 1.641 and 1.625.3 introduced Content-Security-Policy HTTP headers as protection against Cross-Site Scripting attacks using workspace files and archived artifacts served using DirectoryBrowserSupport SECURITY-95

Cucumber Living Documentation Plugin disabled this XSS protection until Jenkins was restarted whenever a Cucumber Report was viewed by any user to work around the Content-Security-Policy limitations.

While disabling this protection mechanism temporarily may be necessary to make plugins work that haven’t been adapted to work with the Content-Security-Policy restriction, this should only be done by administrators, as doing so may result in a security issue (see Configuring Content Security Policy).

This has been addressed in version 1.1.0 of the plugin, and it will now request that users change the Content-Security-Policy option in Jenkins.

SECURITY-373 - Perforce Plugin uses ineffective credentials encryption

Perforce Plugin encrypts its credentials using DES and a public key stored in its public source code, so it only serves as basic obfuscation. This allowed users with Jenkins master local file system access and Jenkins administrators to retrieve the stored password. The latter could result in exposure of the passwords through browser extensions, cross-site scripting vulnerabilities, and similar situations.

As of publication of this advisory, there is no fix. The plugin has been removed from publication at the request of its former maintainers. We recommend that users of Perforce Plugin use the P4 Plugin instead.

SECURITY-504 - vSphere Plugin does not validate SSL/TLS certificates

vSphere Plugin disabled SSL/TLS certificate validation unconditionally, allowing potential man-in-the-middle attacks.

vSphere Plugin 2.17 now has SSL/TLS certificate validation enabled by default.

SECURITY-745 - CSRF vulnerability and missing permission checks in vSphere Plugin form validation allowed enumerating credentials IDs, capturing credentials, and denial of service

vSphere Plugin did not perform permission checks on methods implementing form validation. This allowed users with Overall/Read access to Jenkins to perform various actions such as:

  • Connect to an attacker-specified vSphere server using attacker-specified credentials IDs obtained through another method, capturing credentials stored in Jenkins
  • Connect to configured vSphere servers and looking up information, potentially resulting in denial of service

Additionally, these form validation methods did not require POST requests, resulting in a CSRF vulnerability. These form validation methods now require POST requests and appropriate user permissions.

SECURITY-519 - Liquibase Runner Plugin allows users to load arbitrary Java code into master JVM

Liquibase Runner Plugin allows users with Job/Configure permission to configure its build step in a way that loads arbitrary class files into the Jenkins master JVM, resulting in arbitrary code execution.

As of publication of this advisory, there is no fix.

SECURITY-536 - Perforce Plugin credentials can be obtained by users with Job/Extended Read permission

Jenkins prevents users with Extended Read permission from obtaining secrets such as credentials stored in job configurations.

Perforce Plugin implements its own credential encryption using DES and an encryption key stored in its public source code. This is not considered a secret by Jenkins, resulting in potential exposure of Perforce credentials stored in job configurations to users with Extended Read permission. While these are encrypted, this can only be considered basic obfuscation due to the hard-coded public encryption key used.

As of publication of this advisory, there is no fix.

The plugin has been removed from publication at the request of its maintainers. We recommend that users of Perforce Plugin use the P4 Plugin instead.

SECURITY-545 - Copy To Slave Plugin allows access to arbitrary files on the Jenkins master file system

Copy To Slave Plugin allows users with Job/Configure permissions to configure it in such a way that it allows obtaining arbitrary files accessible to the Jenkins master process from the Jenkins master file system.

As of publication of this advisory, there is no fix.

SECURITY-630 - Ansible Plugin disabled host key verification by default

Ansible Plugin disabled host key verification by default, having it only as an opt-in option. Ansible Plugin 1.0 now enables host key verification by default, adding options allowing users to opt out.

Existing configurations that previously did not opt into host key verification will have host key verification enabled after update, possibly resulting in failures.

SECURITY-736 - Reverse Proxy Auth persisted authorities cache on disk

Reverse Proxy Auth Plugin persisted a cache of granted authorities (group memberships) on disk. This could allow users with local Jenkins master file system access to obtain group membership information of Jenkins users.

Reverse Proxy Auth Plugin 1.6.0 and newer no longer store the cache of granted authorities on disk.

SECURITY-774 - Mailer Plugin allowed unauthorized users to send test emails

A missing permission check in Mailer Plugin allowed users with Overall/Read access to Jenkins to have it connect to a user-specified mail server with user-specified credentials to send a test email to a user-specified email address.

The email subject and body could not be changed. This could result in DoS if, for example, specifying a valid mail server but invalid credentials.

As the same URL did not require POST to be used, it also was vulnerable to cross-site request forgery.

The URL handling test emails now requires POST to protect from CSRF, and performs an Overall/Administer permission check.

 

Severity: 

 

 

Fix: 

 

  • CloudBees Jenkins Enterprise should be upgraded the Managed Masters and Operations Center to 2.107.1.2 revision 3
  • CloudBees Jenkins Platform (rolling train, CJP Operations Center and CJP Client Master 2.x.y.z) should be upgraded to version 2.107.1.2 revision 3
  • CloudBees Jenkins Platform (fixed train, CJP Operations Center and CJP Client Master 2.73.x.0.z) should be upgraded to version 2.73.30.0.1 revision 3
  • CloudBees Jenkins Platform (fixed train, CJP Operations Center and CJP Client Master 2.46.x.0.y) should be upgraded to version 2.46.30.0.1 revision 3
  • CloudBees Jenkins Team should be upgraded to version 2.107.1.2 revision 3
  • DEV@cloud is already protected