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GHSA-w7jr-wqw6-54xc BIT-jenkins-2020-2101 CVE-2020-2101

Non-constant time comparison of inbound TCP agent connection secret

Medium Maven
Severity
5.3 / 10
Medium · CVSS 3.0
Exploit chance (EPSS)
1.37%
Chance of exploitation in the next 30 days. Higher than 71.87% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-203 Observable Discrepancy
CWE-208 Observable Timing Discrepancy
Fix
2.204.2
Upgrade org.jenkins-ci.main:jenkins-core to this version or later

Description

Jenkins 2.218 and earlier, LTS 2.204.1 and earlier does not use a constant-time comparison validating the connection secret when an inbound TCP agent connection is initiated. This could potentially allow attackers to use statistical methods to obtain the connection secret.

Jenkins 2.219, LTS 2.204.2 now uses a constant-time comparison function for verifying connection secrets.

Affected versions

Maven

PackageVulnerableFixed in
org.jenkins-ci.main:jenkins-core
< 2.204.2
2.204.2
org.jenkins-ci.main:jenkins-core
>= 2.205, < 2.219
2.219

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

org.jenkins-ci.main:jenkins-core Maven → 2.204.2

maven
<dependency><groupId>org.jenkins-ci.main</groupId><artifactId>jenkins-core</artifactId><version>2.204.2</version></dependency>
gradle
implementation("org.jenkins-ci.main:jenkins-core:2.204.2")

Severity breakdown

CVSS 3.0 5.3

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

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

Weakness

CWE-203: Observable Discrepancy

The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.

How to prevent it
  • Architecture and Design: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
  • Implementation: Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success. If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files. Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.

CWE-208: Observable Timing Discrepancy

Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-6f9g-cxwr-q5jr
Arbitrary file read vulnerability through the Jenkins CLI can lead to RCE
Critical Known exploited Also affects org.jenkins-ci.main:jenkins-core
GHSA-8pqx-3rxx-f5pm
Jenkins discloses project names via fingerprints
High Known exploited Also affects org.jenkins-ci.main:jenkins-core
GHSA-26wc-3wqp-g3rp
Deserialization of Untrusted Data in Jenkins
Critical Known exploited Also affects org.jenkins-ci.main:jenkins-core
CVE-2018-1000861
Deserialization of Untrusted Data in Jenkins
Critical Known exploited Also affects org.jenkins-ci.main:jenkins-core
GHSA-m6wv-wh8g-64xc
Jenkins does not encrypt secrets from POST config.xml submissions before storing them in job configurations
Medium Also affects org.jenkins-ci.main:jenkins-core
GHSA-93qh-vwrm-c5pw
Jenkins: Stored XSS vulnerability in node offline cause description
Medium Also affects org.jenkins-ci.main:jenkins-core
GHSA-92m7-4fpw-2wxm
Jenkins: Open Redirect phishing attacks possible via "from" parameter in "Delegate to servlet container"
Medium Also affects org.jenkins-ci.main:jenkins-core
GHSA-g28p-6mcc-v4rv
Jenkins exposes other users' timezone and view names to users with Overall/Read permission
Medium Also affects org.jenkins-ci.main:jenkins-core
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