CVE-2022-0415 Overview
CVE-2022-0415 is a Remote Command Execution (RCE) vulnerability in Gogs, a popular self-hosted Git service. The vulnerability exists in the repository file upload functionality, where insufficient validation of the upload TreePath and file name parameters allows authenticated attackers to execute arbitrary commands on the server. Gogs versions prior to 0.12.6 are affected by this security flaw.
Critical Impact
Authenticated attackers can achieve remote command execution on servers running vulnerable Gogs instances, potentially leading to complete system compromise, data exfiltration, and lateral movement within the network.
Affected Products
- Gogs versions prior to 0.12.6
- Self-hosted Gogs installations with file upload functionality enabled
- Any deployment using unpatched gogs:gogs components
Discovery Timeline
- 2022-03-21 - CVE-2022-0415 published to NVD
- 2024-11-21 - Last updated in NVD database
Technical Details for CVE-2022-0415
Vulnerability Analysis
This vulnerability stems from improper input validation (CWE-20) and unrestricted file upload capabilities (CWE-434) in the Gogs repository editor module. The application fails to properly sanitize the TreePath parameter and file names during the repository file upload process, allowing attackers to bypass security controls and execute arbitrary commands.
The attack can be performed remotely over the network by any authenticated user with repository access. No user interaction is required beyond the initial authentication, and successful exploitation results in complete compromise of confidentiality, integrity, and availability of the affected system.
Root Cause
The root cause lies in the internal/db/repo_editor.go file where the upload TreePath and file name parameters are not properly validated before being processed. The absence of path traversal checks and file type restrictions enables attackers to upload malicious files to arbitrary locations or craft specially formatted paths that result in command execution.
Attack Vector
The vulnerability is exploitable over the network by authenticated users. An attacker with valid credentials can:
- Authenticate to the Gogs instance with any repository access
- Navigate to the file upload functionality within a repository
- Craft a malicious TreePath or file name parameter
- Upload a file that triggers command execution on the server
The security patch introduced in commit 0fef3c9082269e9a4e817274942a5d7c50617284 addresses this by implementing proper path validation using the pathutil package:
"strings"
"time"
+ "github.com/pkg/errors"
gouuid "github.com/satori/go.uuid"
"github.com/unknwon/com"
"github.com/gogs/git-module"
"gogs.io/gogs/internal/conf"
"gogs.io/gogs/internal/cryptoutil"
- "gogs.io/gogs/internal/db/errors"
+ dberrors "gogs.io/gogs/internal/db/errors"
"gogs.io/gogs/internal/gitutil"
"gogs.io/gogs/internal/osutil"
+ "gogs.io/gogs/internal/pathutil"
"gogs.io/gogs/internal/process"
"gogs.io/gogs/internal/tool"
)
Source: GitHub Commit Details
Detection Methods for CVE-2022-0415
Indicators of Compromise
- Unusual file upload requests to Gogs repositories with suspicious TreePath parameters containing path traversal sequences (e.g., ../, ..%2f)
- Unexpected files appearing in system directories outside the repository structure
- Abnormal process execution spawned by the Gogs service process
- Web server logs showing malformed upload requests with encoded special characters
Detection Strategies
- Monitor Gogs application logs for file upload operations with unusual path patterns or encoded characters
- Implement web application firewall (WAF) rules to detect path traversal attempts in upload parameters
- Deploy endpoint detection and response (EDR) solutions to identify command execution from Gogs processes
- Review audit logs for authenticated users performing suspicious upload activities
Monitoring Recommendations
- Enable verbose logging for the Gogs application to capture all file upload operations
- Configure alerting on process creation events originating from the Gogs service account
- Monitor network traffic for outbound connections initiated by the Gogs server that could indicate post-exploitation activity
- Implement file integrity monitoring on critical system directories
How to Mitigate CVE-2022-0415
Immediate Actions Required
- Upgrade Gogs to version 0.12.6 or later immediately
- Review Gogs access logs for signs of exploitation attempts
- Audit user accounts with repository access for any unauthorized activity
- Consider temporarily disabling file upload functionality if immediate patching is not possible
Patch Information
The vulnerability has been addressed in Gogs version 0.12.6. The security fix was implemented in commit 0fef3c9082269e9a4e817274942a5d7c50617284, which adds proper validation of the upload TreePath and file name parameters using the pathutil package. Organizations should update to this version or later to remediate the vulnerability. For detailed patch information, refer to the GitHub Commit Details and the Huntr Bounty Report.
Workarounds
- Restrict repository file upload permissions to only trusted administrators until the patch can be applied
- Implement network segmentation to limit the blast radius if the Gogs server is compromised
- Deploy a reverse proxy with strict input validation rules to filter malicious upload requests
- Consider running Gogs in a containerized environment with restricted capabilities to limit post-exploitation impact
# Example: Restrict file upload permissions via Gogs configuration
# Edit app.ini to limit upload capabilities
[repository.upload]
ENABLED = false # Disable file uploads until patched
# Or restrict to specific file types
ALLOWED_TYPES = .md,.txt,.json
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
