CVE-2026-2532: Lintsinghua Deepaudit SSRF Vulnerability

CVE-2026-2532 Overview

CVE-2026-2532 is a Server-Side Request Forgery (SSRF) vulnerability in lintsinghua DeepAudit versions up to 3.0.3. The flaw resides in the IP Address Handler component, specifically in backend/app/api/v1/endpoints/embedding_config.py. An authenticated remote attacker can manipulate input to coerce the server into issuing arbitrary outbound requests. The issue is tracked under [CWE-918] and has been remediated in versions 3.0.4 and 3.1.0 via commit da853fdd8cbe9d42053b45d83f25708ba29b8b27.

Critical Impact
Successful exploitation allows attackers to send crafted requests from the DeepAudit backend to internal services, cloud metadata endpoints, or external systems, potentially exposing sensitive configuration data.

Affected Products

lintsinghua DeepAudit versions up to and including 3.0.3
Fixed in lintsinghua DeepAudit 3.0.4
Fixed in lintsinghua DeepAudit 3.1.0

Discovery Timeline

2026-02-16 - CVE-2026-2532 published to NVD
2026-02-28 - Last updated in NVD database

Technical Details for CVE-2026-2532

Vulnerability Analysis

The vulnerability exists in the embedding configuration endpoint of DeepAudit's backend API. The IP Address Handler accepts user-controlled input without sufficient validation against internal address ranges, loopback interfaces, or cloud metadata endpoints. An attacker with low-privilege authenticated access can submit a crafted address that causes the backend to perform an outbound HTTP request on behalf of the application.

Server-Side Request Forgery in this context allows pivoting from the externally exposed API into the internal network perimeter. Attackers can probe internal services, fingerprint hosts, or attempt to read cloud instance metadata such as IAM credentials from endpoints like 169.254.169.254. The vulnerability requires network-level access and authenticated context to exploit.

Root Cause

The root cause is missing or insufficient SSRF protection logic in the embedding configuration handler. The patch commit da853fdd8cbe9d42053b45d83f25708ba29b8b27 is titled "修复SSRF防护实现的问题" (fix: SSRF protection implementation issue), confirming that prior validation logic failed to properly restrict outbound destinations.

Attack Vector

The attack is performed remotely over the network against the DeepAudit API. The attacker submits a manipulated IP address or URL to the embedding_config.py endpoint. The backend then initiates a request to the attacker-supplied destination, returning response data or behavior that can be analyzed for internal reconnaissance.

python

# Patch excerpt from backend/app/api/v1/endpoints/embedding_config.py
# fix: 修复SSRF防护实现的问题

"""
 使用 UserConfig.other_config 持久化存储
"""

import asyncio
import json
import time
import uuid
from typing import Any, Optional, List
from fastapi import APIRouter, Depends, HTTPException

Source: GitHub Commit da853fdd

Detection Methods for CVE-2026-2532

Indicators of Compromise

Outbound HTTP requests from the DeepAudit backend host to internal RFC1918 ranges, 127.0.0.1, or cloud metadata addresses such as 169.254.169.254.
Unexpected POST or PUT requests to /api/v1/endpoints/embedding_config containing IP addresses or URLs in payload fields.
Anomalous DNS resolutions originating from the DeepAudit application server pointing to internal hostnames.

Detection Strategies

Inspect application logs for embedding configuration submissions referencing loopback, link-local, or private IP ranges.
Correlate authenticated user sessions making embedding_config API calls with outbound network connections from the backend service.
Deploy egress filtering and alert on backend-initiated traffic to non-allowlisted destinations.

Monitoring Recommendations

Enable verbose request logging on the FastAPI backend including source IP, user identifier, and request body for the embedding configuration endpoint.
Monitor for elevated rates of 4xx or 5xx responses from embedding_config.py indicating probing behavior.
Forward web server and application telemetry to a centralized analytics platform for correlation against outbound traffic flows.

How to Mitigate CVE-2026-2532

Immediate Actions Required

Upgrade DeepAudit to version 3.0.4 or 3.1.0 immediately to apply the official SSRF protection fix.
Restrict network egress from the DeepAudit backend to only the destinations required for embedding provider APIs.
Audit existing embedding configurations for entries pointing to internal addresses and remove any suspicious records.

Patch Information

The vendor released the fix in commit da853fdd8cbe9d42053b45d83f25708ba29b8b27, merged via Pull Request #145 and shipped in Release v3.0.4. Refer to the GitHub Issue Discussion for original disclosure context and VulDB #346120 for advisory metadata.

Workarounds

Place the DeepAudit backend behind a network policy that blocks access to internal subnets, loopback, and cloud metadata endpoints.
Require an authenticated reverse proxy that validates embedding configuration payloads before forwarding to the application.
Limit embedding configuration management privileges to a minimal set of trusted administrative users until patched.

bash

# Example egress restriction using iptables on the DeepAudit host
iptables -A OUTPUT -d 169.254.169.254 -j DROP
iptables -A OUTPUT -d 127.0.0.0/8 -j DROP
iptables -A OUTPUT -d 10.0.0.0/8 -j DROP
iptables -A OUTPUT -d 172.16.0.0/12 -j DROP
iptables -A OUTPUT -d 192.168.0.0/16 -j DROP