Jenkins LTS < 2.303.3 / Jenkins weekly < 2.319 Multiple Vulnerabilities

critical Nessus Plugin ID 154894

Synopsis

An application running on a remote web server host is affected by multiple vulnerabilities

Description

According to its its self-reported version number, the version of Jenkins running on the remote web server is Jenkins LTS prior to 2.303.3 or Jenkins weekly prior to 2.319. It is, therefore, affected by multiple vulnerabilities:

- Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not check agent-to-controller access to create parent directories in FilePath#mkdirs. (CVE-2021-21685)

- File path filters in the agent-to-controller security subsystem of Jenkins 2.318 and earlier, LTS 2.303.2 and earlier do not canonicalize paths, allowing operations to follow symbolic links to outside allowed directories. (CVE-2021-21686)

- Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not check agent-to-controller access to create symbolic links when unarchiving a symbolic link in FilePath#untar. (CVE-2021-21687)

- The agent-to-controller security check FilePath#reading(FileVisitor) in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not reject any operations, allowing users to have unrestricted read access using certain operations (creating archives, FilePath#copyRecursiveTo). (CVE-2021-21688)

- FilePath#unzip and FilePath#untar were not subject to any agent-to-controller access control in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier. (CVE-2021-21689)

- Agent processes are able to completely bypass file path filtering by wrapping the file operation in an agent file path in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier. (CVE-2021-21690)

- Creating symbolic links is possible without the 'symlink' agent-to-controller access control permission in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier. (CVE-2021-21691)

- FilePath#renameTo and FilePath#moveAllChildrenTo in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier only check 'read' agent-to-controller access permission on the source path, instead of 'delete'.
(CVE-2021-21692)

- When creating temporary files, agent-to-controller access to create those files is only checked after they've been created in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier. (CVE-2021-21693)

- FilePath#toURI, FilePath#hasSymlink, FilePath#absolutize, FilePath#isDescendant, and FilePath#get*DiskSpace do not check any permissions in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier.
(CVE-2021-21694)

- FilePath#listFiles lists files outside directories that agents are allowed to access when following symbolic links in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier. (CVE-2021-21695)

- Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not limit agent read/write access to the libs/ directory inside build directories when using the FilePath APIs, allowing attackers in control of agent processes to replace the code of a trusted library with a modified variant. This results in unsandboxed code execution in the Jenkins controller process. (CVE-2021-21696)

- Jenkins 2.318 and earlier, LTS 2.303.2 and earlier allows any agent to read and write the contents of any build directory stored in Jenkins with very few restrictions. (CVE-2021-21697)

- Jenkins Subversion Plugin 2.15.0 and earlier does not restrict the name of a file when looking up a subversion key file on the controller from an agent. (CVE-2021-21698)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade Jenkins weekly to version 2.319 or later or Jenkins LTS to version 2.303.3 or later

See Also

https://jenkins.io/security/advisory/2021-11-04

Plugin Details

Severity: Critical

ID: 154894

File Name: jenkins_2_319.nasl

Version: 1.6

Type: combined

Agent: windows, macosx, unix

Family: CGI abuses

Published: 11/4/2021

Updated: 4/11/2022

Supported Sensors: Nessus Agent

Risk Information

CVSS Score Source: CVE-2021-21696

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:cloudbees:jenkins, cpe:/a:jenkins:jenkins

Required KB Items: installed_sw/Jenkins

Exploit Ease: No known exploits are available

Patch Publication Date: 11/4/2021

Vulnerability Publication Date: 11/4/2021

Reference Information

CVE: CVE-2021-21685, CVE-2021-21686, CVE-2021-21687, CVE-2021-21688, CVE-2021-21689, CVE-2021-21690, CVE-2021-21691, CVE-2021-21692, CVE-2021-21693, CVE-2021-21694, CVE-2021-21695, CVE-2021-21696, CVE-2021-21697, CVE-2021-21698

IAVA: 2021-A-0551-S