CVE-2025-68703: Jervis Library Weak Encryption Vulnerability

CVE-2025-68703 Overview

CVE-2025-68703 is a weak cryptographic key derivation vulnerability affecting Jervis, a library for Job DSL plugin scripts and shared Jenkins pipeline libraries. Prior to version 2.2, the encryption implementation derives the salt directly from sha256Sum(passphrase), which means that two encryption operations using the same password will produce identical derived keys. This cryptographic weakness significantly undermines the security of encrypted data within Jenkins pipelines and could allow attackers to perform cryptanalysis attacks against encrypted secrets.

Critical Impact

Deterministic key derivation allows attackers to identify when the same passphrase is used across multiple encryption operations, potentially enabling rainbow table attacks, key recovery, and exposure of encrypted secrets in Jenkins CI/CD environments.

Affected Products

• Jervis library versions prior to 2.2
• Jenkins environments using vulnerable Jervis Job DSL plugin scripts
• Jenkins pipelines leveraging affected shared libraries

Discovery Timeline

• 2026-01-13 - CVE CVE-2025-68703 published to NVD
• 2026-01-13 - Last updated in NVD database

Technical Details for CVE-2025-68703

Vulnerability Analysis

This vulnerability falls under CWE-326 (Inadequate Encryption Strength) and stems from a fundamental cryptographic design flaw in how Jervis handles encryption key derivation. The library's encryption mechanism deterministically computes the salt by applying SHA-256 to the user-provided passphrase. In proper cryptographic implementations, salts should be randomly generated and unique for each encryption operation to prevent pre-computation attacks and ensure that identical plaintexts encrypted with the same key produce different ciphertexts.

When the salt is derived deterministically from the passphrase, it becomes constant for any given password. This eliminates the cryptographic diversity that salts are meant to provide, making the encryption vulnerable to several attack scenarios including rainbow table attacks, known-plaintext analysis, and frequency analysis when the same password protects multiple secrets.

Root Cause

The root cause lies in the cryptographic implementation where sha256Sum(passphrase) is used to derive the salt value. This approach conflates the salt with the key material, violating the cryptographic principle that salts must be random and unique. The deterministic nature means attackers who observe multiple ciphertexts can identify when identical passphrases were used and leverage this information for cryptanalysis.

Attack Vector

The attack vector is network-based, requiring no user interaction or special privileges. An attacker with access to encrypted data within Jenkins pipelines or Job DSL configurations could:

1. Collect multiple encrypted values protected by the same passphrase
2. Identify encryption patterns due to the deterministic salt derivation
3. Perform offline attacks including dictionary attacks optimized by the deterministic key derivation
4. Potentially recover the passphrase or derive equivalent keys through cryptanalysis

The vulnerability is particularly dangerous in CI/CD environments where secrets management is critical and multiple encrypted values may share the same passphrase. Technical details can be found in the GitHub Security Advisory GHSA-36h5-vrq6-pp34.

Detection Methods for CVE-2025-68703

Indicators of Compromise

• Presence of Jervis library versions prior to 2.2 in Jenkins plugin directories
• Jenkins pipeline scripts importing vulnerable Jervis encryption utilities
• Job DSL configurations utilizing the affected cryptographic functions
• Unusual access patterns to encrypted secrets or configuration files

Detection Strategies

• Audit Jenkins environments for Jervis library version using dependency scanning tools
• Review pipeline code for usage of Jervis encryption methods with static code analysis
• Monitor for unauthorized access to Jenkins credential stores and encrypted configuration files
• Implement software composition analysis (SCA) to identify vulnerable library versions

Monitoring Recommendations

• Configure alerts for Jervis library usage in Jenkins builds and deployments
• Monitor Jenkins audit logs for bulk access to encrypted secrets
• Track changes to shared library configurations that reference Jervis encryption utilities
• Implement continuous monitoring for vulnerable dependency versions across CI/CD infrastructure

How to Mitigate CVE-2025-68703

Immediate Actions Required

• Upgrade Jervis library to version 2.2 or later immediately across all Jenkins instances
• Rotate all secrets that were encrypted using vulnerable Jervis versions
• Audit all Jenkins pipelines and Job DSL scripts for affected encryption usage
• Review and re-encrypt any credentials that may have been protected with the vulnerable implementation

Patch Information

The vulnerability is fixed in Jervis version 2.2. The fix introduces proper random salt generation for encryption operations, ensuring cryptographic uniqueness. The specific commit addressing this vulnerability can be reviewed at the GitHub Commit. Organizations should update their Jenkins shared libraries and plugin dependencies to incorporate the patched version.

Workarounds

• If immediate upgrade is not possible, avoid using Jervis encryption functions until patched
• Implement external secrets management solutions (HashiCorp Vault, AWS Secrets Manager) as an alternative
• Isolate Jenkins environments using vulnerable Jervis versions from sensitive operations
• Apply network segmentation to limit access to Jenkins instances with unpatched libraries