CVE-2021-45327
📋 TL;DR
CVE-2021-45327 is a server-side request forgery (SSRF) vulnerability in Gitea's admin and user API endpoints that improperly trusts HTTP permission methods. This allows remote attackers to execute arbitrary code on affected Gitea instances. All Gitea installations before version 1.11.2 are vulnerable.
💻 Affected Systems
- Gitea
📦 What is this software?
Gitea by Gitea
⚠️ Risk & Real-World Impact
Worst Case
Remote unauthenticated attacker gains full system compromise, executes arbitrary code with Gitea process privileges, and potentially pivots to other systems.
Likely Case
Attacker gains administrative access to Gitea instance, modifies repositories, steals source code, and potentially executes code within the Gitea application context.
If Mitigated
With proper network segmentation and least privilege, impact limited to Gitea application compromise without system-level access.
🎯 Exploit Status
Exploitation requires network access to Gitea API endpoints. Multiple public references demonstrate the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.11.2 and later
Vendor Advisory: https://blog.gitea.io/2020/03/gitea-1.11.2-is-released/
Restart Required: Yes
Instructions:
1. Backup Gitea data and configuration. 2. Stop Gitea service. 3. Update to Gitea 1.11.2 or later using package manager or manual installation. 4. Restart Gitea service. 5. Verify version and functionality.
🔧 Temporary Workarounds
Network Access Control
linuxRestrict network access to Gitea API endpoints using firewall rules
iptables -A INPUT -p tcp --dport 3000 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 3000 -j DROP
Reverse Proxy Filtering
allConfigure reverse proxy to block malicious API requests
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Gitea from sensitive systems
- Deploy web application firewall with SSRF protection rules
🔍 How to Verify
Check if Vulnerable:
Check Gitea version via web interface or command: gitea --versionCheck Version:
gitea --versionVerify Fix Applied:
Confirm version is 1.11.2 or higher and test API endpoints for proper permission validation📡 Detection & Monitoring
Log Indicators:
- Unusual API requests to admin/user endpoints
- Requests with manipulated HTTP methods
- Unexpected process execution from Gitea
Network Indicators:
- External connections from Gitea to internal services
- Unusual outbound traffic patterns
SIEM Query:
source="gitea.log" AND ("API" OR "admin" OR "user") AND ("POST" OR "PUT" OR "DELETE") AND status=200🔗 References
- https://blog.gitea.io/2020/03/gitea-1.11.2-is-released/
- https://github.com/go-gitea/gitea/pull/10462
- https://github.com/go-gitea/gitea/pull/10465
- https://github.com/go-gitea/gitea/pull/10582
- https://blog.gitea.io/2020/03/gitea-1.11.2-is-released/
- https://github.com/go-gitea/gitea/pull/10462
- https://github.com/go-gitea/gitea/pull/10465
- https://github.com/go-gitea/gitea/pull/10582
