CVE-2025-68698 Overview
CVE-2025-68698 is a cryptographic vulnerability affecting Jervis, a library for Job DSL plugin scripts and shared Jenkins pipeline libraries. Prior to version 2.2, Jervis uses PKCS1Encoding which is vulnerable to Bleichenbacher padding oracle attacks. This weakness in cryptographic implementation allows attackers to potentially decrypt encrypted data or forge signatures by exploiting the padding validation oracle. Modern systems should use OAEP (Optimal Asymmetric Encryption Padding) for secure RSA encryption operations.
Critical Impact
Attackers can exploit the Bleichenbacher padding oracle attack to decrypt sensitive data or forge cryptographic signatures in Jenkins CI/CD pipelines using affected Jervis library versions.
Affected Products
- Jervis library versions prior to 2.2
- Jenkins installations using vulnerable Jervis Job DSL plugin scripts
- Jenkins shared pipeline libraries utilizing affected Jervis versions
Discovery Timeline
- 2026-01-13 - CVE CVE-2025-68698 published to NVD
- 2026-01-13 - Last updated in NVD database
Technical Details for CVE-2025-68698
Vulnerability Analysis
This vulnerability (CWE-327: Use of a Broken or Risky Cryptographic Algorithm) stems from the use of PKCS#1 v1.5 padding in RSA encryption operations. The Bleichenbacher attack, first discovered in 1998, remains a significant threat when systems use PKCS1Encoding for RSA operations. The attack leverages timing or error message differences when processing encrypted messages to gradually recover plaintext through an adaptive chosen-ciphertext attack.
In the context of Jervis, this vulnerability could allow an attacker with network access to observe encryption/decryption operations and systematically derive the private key or decrypt sensitive data processed by Jenkins pipelines. The attack is particularly concerning in CI/CD environments where cryptographic operations may protect secrets, credentials, or sensitive build artifacts.
Root Cause
The root cause is the use of PKCS#1 v1.5 encoding (PKCS1Encoding) for RSA encryption operations instead of the more secure OAEP (Optimal Asymmetric Encryption Padding). PKCS#1 v1.5 padding is inherently vulnerable to padding oracle attacks because the padding structure allows attackers to distinguish between valid and invalid padding through observable side channels. The fix in version 2.2 migrates to OAEP padding, which includes randomized padding and prevents the padding oracle attack vector.
Attack Vector
The attack requires network access to systems running vulnerable Jervis library versions. An attacker can exploit this vulnerability by:
- Intercepting or collecting encrypted messages processed by the vulnerable Jervis library
- Sending crafted ciphertext modifications to the target system
- Observing the system's response (timing differences, error messages, or behavior changes)
- Using adaptive chosen-ciphertext techniques to iteratively recover the plaintext
The Bleichenbacher attack typically requires thousands of oracle queries but can be optimized with modern techniques. Once successful, the attacker can decrypt sensitive data or forge valid signatures without possessing the private key.
Detection Methods for CVE-2025-68698
Indicators of Compromise
- Unusual volume of cryptographic operation requests to Jenkins/Jervis endpoints
- Repeated decryption or signature verification failures in application logs
- Network traffic patterns consistent with adaptive chosen-ciphertext attacks
- Anomalous timing patterns in cryptographic operation responses
Detection Strategies
- Monitor Jenkins logs for repeated cryptographic errors or padding-related exceptions
- Implement rate limiting on cryptographic operations to detect brute-force oracle attacks
- Use application performance monitoring to detect timing anomalies in encryption/decryption operations
- Audit dependency versions to identify Jervis installations below version 2.2
Monitoring Recommendations
- Enable verbose logging for cryptographic operations in Jenkins environments
- Deploy network intrusion detection systems to identify patterns consistent with padding oracle attacks
- Implement anomaly detection for Jenkins API endpoints handling encrypted data
- Regularly audit Jenkins plugin and library versions against known vulnerabilities
How to Mitigate CVE-2025-68698
Immediate Actions Required
- Upgrade Jervis library to version 2.2 or later immediately
- Audit all Jenkins installations for vulnerable Jervis versions
- Review and rotate any cryptographic keys that may have been exposed
- Monitor Jenkins environments for signs of active exploitation
Patch Information
The vulnerability is fixed in Jervis version 2.2. The patch migrates from PKCS1Encoding to OAEP (Optimal Asymmetric Encryption Padding), eliminating the padding oracle attack vector. Technical details of the fix can be found in the GitHub Commit Details. For additional security information, refer to the GitHub Security Advisory.
Workarounds
- If immediate upgrade is not possible, consider implementing network-level access controls to limit exposure
- Implement rate limiting on cryptographic operations to slow down potential oracle attacks
- Add additional logging and monitoring to detect exploitation attempts
- Consider temporarily disabling vulnerable cryptographic functionality if feasible
# Update Jervis library to patched version
# In your build.gradle or pom.xml, update dependency:
# implementation 'net.gleske:jervis:2.2'
# or
# <version>2.2</version>
# Verify the installed version
grep -r "jervis" build.gradle pom.xml | grep version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
