CVE-2025-59355: 
Java vulnerability analysis and mitigation

CVE-2025-59355 is a password exposure vulnerability in Apache Linkis affecting versions 1.0.0 through 1.7.0. When org.apache.linkis.metadata.util.HiveUtils.decode() fails to perform Base64 decoding, it logs the complete input parameter string — including plaintext passwords — via logger.error(str + "decode failed", e). This can expose sensitive credentials such as Hive Metastore connection passwords configured in hive-site.xml. The vulnerability was publicly disclosed on September 19, 2025, and carries a CVSS v3.1 base score of 6.5 (Medium) (Red Hat CVE, oss-security).

The root cause is classified as CWE-532 (Insertion of Sensitive Information into Log File). The vulnerable method HiveUtils.decode() attempts Base64 decoding of configuration values from hive-site.xml (e.g., javax.jdo.option.ConnectionPassword); when decoding fails due to an invalid Base64 string, the raw input — potentially containing plaintext credentials — is concatenated directly into the error log message. Exploitation requires two conditions: the configuration value must be an invalid Base64 string, and the resulting error-level log files must be readable by users who are not authorized administrators of hive-site.xml. The attack vector is network-accessible (CVSS AV:N) with low privileges required and no user interaction (oss-security, Red Hat CVE).

Successful exploitation results in exposure of sensitive credentials — specifically plaintext database passwords or Hive Metastore keys — written to application log files. The confidentiality impact is rated High (CVSS C:H), while integrity and availability are unaffected. An attacker with read access to Linkis log files could harvest database credentials, potentially enabling lateral movement to backend data stores such as Hive Metastore or connected relational databases (oss-security, Red Hat CVE).

1. Identify target: Locate an Apache Linkis deployment running versions 1.0.0–1.7.0 with Hive Metastore integration configured.
2. Trigger decoding failure: Ensure or observe that a sensitive configuration field in hive-site.xml (e.g., javax.jdo.option.ConnectionPassword) contains an invalid Base64 string, which causes HiveUtils.decode() to throw an exception.
3. Access log files: Obtain read access to Linkis application log files (e.g., linkis.log or equivalent) that capture error-level log output — this may be possible for low-privileged users on the same system or via misconfigured log aggregation systems.
4. Extract credentials: Search log files for entries containing decode failed to locate lines where the raw input string (including plaintext passwords) was logged by logger.error(str + "decode failed", e).
5. Leverage credentials: Use the extracted database credentials to authenticate directly to the Hive Metastore or connected database, enabling unauthorized data access or lateral movement (oss-security).

• Logs: Presence of log entries matching the pattern <sensitive_value> decode failed in Linkis error logs, particularly in files associated with the org.apache.linkis.metadata.util.HiveUtils class; unexpected access or reads of Linkis log files by non-administrative users.
• File System: Linkis log files (e.g., linkis.log, linkis-error.log) with world-readable or group-readable permissions that expose error-level output containing configuration values.
• Process/Access: Unusual access patterns to Hive Metastore or backend databases using credentials that match those stored in hive-site.xml, particularly from unexpected source IPs or accounts (oss-security).

Users should upgrade to Apache Linkis 1.8.0 or later, which replaces the vulnerable log statement with a desensitized version: logger.error("URL decode failed: {}", e.getMessage()); — omitting the raw input string from log output. As an interim workaround, administrators should restrict read permissions on Linkis log files to authorized administrators only, and audit hive-site.xml to ensure sensitive fields contain valid Base64-encoded values. Rotating any credentials that may have been exposed in existing log files is also recommended (oss-security, Red Hat CVE).

The vulnerability was disclosed via the Apache security mailing list and oss-security on September 19, 2025, by researcher Chen Xia, with credit to Kyler (finder), kinghao (analyst and reviewer), and Le1a (remediation developer). Red Hat has tracked the CVE in their security advisory database. Community reaction has been minimal given the low severity rating and limited exploitation potential (oss-security, Red Hat CVE).