CVE-2025-27528: Apache InLong Information Disclosure Flaw

CVE-2025-27528 Overview

CVE-2025-27528 is a critical Deserialization of Untrusted Data vulnerability affecting Apache InLong, a widely-used one-stop integration framework for massive data. This vulnerability allows remote attackers to bypass security mechanisms implemented in the InLong JDBC component, ultimately enabling arbitrary file reading on affected systems. The flaw stems from improper handling of serialized data, which can be exploited without authentication over the network.

Critical Impact

This vulnerability enables unauthenticated attackers to bypass InLong JDBC security controls and read arbitrary files from the server, potentially exposing sensitive configuration data, credentials, and other confidential information.

Affected Products

• Apache InLong versions 1.13.0 through 2.1.0
• Apache InLong JDBC component

Discovery Timeline

• 2025-05-28 - CVE-2025-27528 published to NVD
• 2025-06-03 - Last updated in NVD database

Technical Details for CVE-2025-27528

Vulnerability Analysis

This vulnerability is classified as CWE-502 (Deserialization of Untrusted Data), a well-known weakness that occurs when an application deserializes data from untrusted sources without proper validation. In the context of Apache InLong, the JDBC component fails to adequately validate or sanitize serialized objects before processing them.

The attack can be performed remotely without requiring any privileges or user interaction. Successful exploitation results in high impact to both confidentiality and integrity of the affected system, though availability remains unaffected. The vulnerability specifically allows attackers to circumvent the security mechanisms that InLong JDBC normally enforces, creating a path to read arbitrary files from the underlying file system.

Root Cause

The root cause lies in the deserialization logic within the Apache InLong JDBC component. When processing incoming data, the component deserializes objects without implementing sufficient security controls to validate the integrity and origin of the serialized data. This allows an attacker to craft malicious serialized payloads that, when processed by the vulnerable component, execute unintended operations that bypass the normal security restrictions.

The fix implemented in pull request #11747 addresses this by adding proper validation checks to the deserialization process, ensuring that only expected and safe data structures are processed.

Attack Vector

The attack vector is network-based, allowing remote exploitation. An attacker can target an exposed Apache InLong instance by sending specially crafted serialized data to the JDBC component. The attack flow typically involves:

1. Identifying an Apache InLong instance running a vulnerable version (1.13.0 through 2.1.0)
2. Crafting a malicious serialized payload designed to exploit the deserialization flaw
3. Sending the payload to the JDBC component endpoint
4. Bypassing security mechanisms and reading arbitrary files from the server

The vulnerability does not require any authentication or user interaction, making it particularly dangerous for internet-facing deployments. Technical details regarding the specific exploitation mechanism can be found in the Openwall OSS Security Discussion.

Detection Methods for CVE-2025-27528

Indicators of Compromise

• Unusual file access patterns in Apache InLong logs, particularly attempts to read sensitive system files
• Anomalous JDBC connection requests containing unexpected serialized data patterns
• Access attempts to configuration files, credential stores, or other sensitive paths through InLong
• Suspicious network traffic to InLong JDBC endpoints with non-standard payloads

Detection Strategies

• Monitor Apache InLong application logs for deserialization errors or exceptions that may indicate exploitation attempts
• Implement network intrusion detection rules to identify malicious serialized Java objects in traffic to InLong services
• Deploy file integrity monitoring on sensitive directories to detect unauthorized file access
• Enable verbose logging on InLong JDBC components to capture detailed request information

Monitoring Recommendations

• Set up alerts for any file read operations outside of expected InLong data directories
• Monitor for connection attempts from unusual IP addresses or geographic locations
• Implement rate limiting and anomaly detection on JDBC endpoints to identify scanning or exploitation attempts
• Review access logs regularly for patterns consistent with reconnaissance or exploitation activity

How to Mitigate CVE-2025-27528

Immediate Actions Required

• Upgrade Apache InLong to version 2.2.0 or later, which contains the security fix
• If immediate upgrade is not possible, apply the patch from GitHub pull request #11747
• Restrict network access to InLong JDBC endpoints to trusted IP addresses only
• Review file access logs for signs of prior exploitation

Patch Information

Apache has released version 2.2.0 of InLong which addresses this vulnerability. Users running affected versions (1.13.0 through 2.1.0) should upgrade immediately. For users unable to perform a full upgrade, the specific fix can be cherry-picked from pull request #11747 on the Apache InLong GitHub repository.

Additional details are available in the Apache Mailing List Thread.

Workarounds

• Implement network segmentation to isolate Apache InLong instances from untrusted networks
• Deploy a web application firewall (WAF) with rules to detect and block malicious serialized payloads
• Restrict file system permissions to limit the files that can be read by the InLong process
• Consider disabling or restricting access to the JDBC component if not actively required until patching is complete

# Example: Restrict InLong JDBC access via iptables
iptables -A INPUT -p tcp --dport 8083 -s trusted_ip_range -j ACCEPT
iptables -A INPUT -p tcp --dport 8083 -j DROP