Executive Summary

CVE-2026-2532 is a server-side request forgery (SSRF) vulnerability found in lintsinghua DeepAudit versions up to 3.0.3. It exists in the IP Address Handler component within the file backend/app/api/v1/endpoints/embedding_config.py.

The vulnerability occurs because the system does not properly validate or normalize IP addresses, especially IPv6-mapped IPv4 addresses, allowing attackers to bypass internal IP range checks. This enables an attacker to manipulate input remotely to make the server perform unauthorized requests to internal or protected network resources.

Specifically, the validation logic fails to recognize IPv6-mapped IPv4 addresses (e.g., ::ffff:127.0.0.1) as internal IPs, allowing malicious URLs to bypass protections and trigger SSRF attacks.

The issue can be mitigated by upgrading DeepAudit to versions 3.0.4 or 3.1.0, which include patches that improve SSRF protection by enforcing fixed response times and adjusting latency calculations, although some recommended improvements remain.

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Impact Analysis

This SSRF vulnerability allows an attacker to remotely induce the vulnerable server to make unauthorized requests to internal or protected network resources.

Potential impacts include unauthorized access to sensitive internal services, exposure of confidential information, manipulation or disruption of internal systems, and possible compromise of system integrity and availability.

Additionally, the vulnerability can be exploited to perform internal port scanning, which may reveal network topology and services, aiding further attacks.

The vulnerability has a medium severity level with a CVSSv3 base score of 6.3, indicating a significant risk that should be addressed promptly.

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Compliance Impact

I don't know

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Detection Guidance

[{'type': 'paragraph', 'content': 'The vulnerability in DeepAudit involves a Server-Side Request Forgery (SSRF) flaw in the IP Address Handler component, specifically in the file backend/app/api/v1/endpoints/embedding_config.py. Detection involves identifying attempts to exploit SSRF by monitoring requests that manipulate URLs or IP addresses, especially those using IPv6-mapped IPv4 addresses to bypass internal IP range checks.'}, {'type': 'paragraph', 'content': 'Since the vulnerability allows attackers to bypass internal IP range validation by using IPv6-mapped IPv4 addresses (e.g., ::ffff:127.0.0.1), detection can focus on monitoring incoming requests for such patterns.'}, {'type': 'paragraph', 'content': 'Suggested detection commands or methods include:'}, {'type': 'list_item', 'content': 'Monitor web server logs for requests containing IPv6-mapped IPv4 addresses, such as URLs with patterns like http://[::ffff:127.0.0.1]:port.'}, {'type': 'list_item', 'content': 'Use network monitoring tools (e.g., tcpdump, Wireshark) to capture and analyze HTTP requests targeting internal IP ranges or unusual hostnames.'}, {'type': 'list_item', 'content': "Implement custom scripts or use log analysis tools (e.g., grep, awk) to search for suspicious request patterns in application logs, for example: grep -E '\\[::ffff:[0-9a-fA-F:.]+\\]' /var/log/deepaudit/access.log"}, {'type': 'list_item', 'content': 'Check for abnormal timing patterns in responses, as the patched versions introduce fixed response times to mitigate SSRF port scanning.'}, {'type': 'paragraph', 'content': 'Note that no public exploit code is available, so detection relies on monitoring for suspicious request patterns and timing anomalies related to SSRF attempts.'}] [1, 4]

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Mitigation Strategies

The primary and recommended immediate mitigation step is to upgrade lintsinghua DeepAudit to version 3.0.4 or 3.1.0, which include patches addressing the SSRF vulnerability.

The patch (commit da853fdd8cbe9d42053b45d83f25708ba29b8b27) improves SSRF protection by:

• Implementing fixed response times to prevent SSRF port scanning via timing attacks.
• Correcting latency calculation to accurately reflect embedding operation time.
• Reducing fixed delay duration from 10 seconds to 3 seconds to improve user experience.

However, the patch does not fully resolve the SSRF vulnerability because it lacks proper URL validation and normalization of IPv6-mapped IPv4 addresses.

Additional recommended mitigation steps include:

• Implement or verify that the application normalizes IPv6-mapped IPv4 addresses to their IPv4 equivalents before IP range validation.
• Ensure internal IP ranges include IPv6-mapped IPv4 ranges explicitly in the blocklist.
• Add robust validation mechanisms for URLs and IP addresses to prevent SSRF bypass.
• Enhance error handling to avoid exposing sensitive exception details.
• Add security logging to detect and audit suspicious SSRF attempts.

In summary, immediate mitigation is upgrading to the fixed versions, followed by applying recommended security best practices to strengthen SSRF protections.

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