CVE-2024-39932: Gogs Argument Injection RCE Vulnerability

CVE-2024-39932 Overview

CVE-2024-39932 is an argument injection vulnerability affecting Gogs self-hosted Git service through version 0.13.0. The flaw exists in the change preview functionality, where attacker-controlled input is passed as arguments to Git command-line operations. Authenticated users with write access to a repository can inject Git command flags during the diff preview process, leading to arbitrary code execution on the host server. The vulnerability is tracked under CWE-94: Improper Control of Generation of Code. SonarSource researchers documented the issue as part of a broader review of unpatched Gogs vulnerabilities.

Critical Impact

Authenticated attackers can execute arbitrary commands on the Gogs server, leading to full compromise of source code repositories, credentials, and the underlying host system.

Affected Products

• Gogs through version 0.13.0
• All self-hosted Gogs instances exposing the change preview feature
• Deployments where authenticated users can submit diff previews

Discovery Timeline

• 2024-07-04 - CVE-2024-39932 published to NVD
• 2025-04-10 - Last updated in NVD database

Technical Details for CVE-2024-39932

Vulnerability Analysis

The vulnerability resides in the Gogs change-preview code path, which invokes the underlying git binary to render diffs. User-supplied parameters from the preview request are concatenated into the Git command line without sufficient separation between options and operands. Because Git supports a wide range of command-line flags that can alter execution behavior, an attacker who controls one of these arguments can transform a benign read operation into one that executes arbitrary code.

The issue maps to CWE-94: Improper Control of Generation of Code. The EPSS probability of 3.23% places this CVE in the 87th percentile of CVEs by exploitation likelihood, indicating elevated attacker interest relative to most published vulnerabilities. Refer to the SonarSource analysis of Gogs vulnerabilities for the full technical breakdown.

Root Cause

The root cause is the absence of an argument terminator (--) and inadequate validation of user-controlled values before they are passed to git subcommands. When a value begins with a - or --, Git interprets it as an option rather than a positional argument such as a file path or revision identifier.

Attack Vector

Exploitation requires an authenticated account with permission to trigger the preview function on a repository. The attacker crafts a request containing a filename or revision argument that Git parses as a flag enabling external command execution. The malicious flag causes git to spawn an attacker-controlled process under the Gogs service account. Because the attack uses the network-facing web interface, no local access to the server is required.

No verified public exploit code is available for inclusion. See the SonarSource advisory for technical reproduction details.

Detection Methods for CVE-2024-39932

Indicators of Compromise

• Unexpected child processes spawned by the Gogs service account, particularly shells or interpreters such as sh, bash, python, or perl
• HTTP requests to Gogs preview or diff endpoints containing parameters beginning with - or --
• New or modified SSH keys, webhooks, or deploy keys appearing in repository configuration without administrator action
• Outbound network connections originating from the Gogs host to unfamiliar destinations

Detection Strategies

• Inspect Gogs application logs for preview requests with suspicious revision or path parameters containing flag-like syntax
• Correlate web access logs with process creation events on the Gogs host to identify command execution following diff preview requests
• Monitor the parent-child process relationship under the gogs user for any non-git child executions

Monitoring Recommendations

• Forward Gogs HTTP access logs and host process telemetry to a centralized analytics platform for correlation
• Alert on any execution of shells or scripting interpreters as descendants of the Gogs process
• Review repository audit logs for unauthorized changes to hooks, settings, or access tokens

How to Mitigate CVE-2024-39932

Immediate Actions Required

• Upgrade Gogs to a version later than 0.13.0 that addresses the argument injection flaw; consult the Gogs release notes for the current fixed release
• Restrict Gogs to trusted authenticated users and disable open registration until patching is complete
• Rotate credentials, deploy keys, and webhook secrets stored on the Gogs instance if exposure is suspected
• Audit repository hooks and server-side configuration files for unauthorized modifications

Patch Information

Review the Gogs GitHub releases page for the latest version and apply the upgrade following the project's documented procedure. The SonarSource disclosure documents the patch status at the time of publication and should be consulted to confirm fixed versions.

Workarounds

• Place the Gogs web interface behind a reverse proxy or web application firewall that blocks request parameters containing -- prefixes in revision or path fields
• Run the Gogs process as an unprivileged user inside a hardened container with restricted egress to limit post-exploitation impact
• Disable or restrict access to the change preview feature for untrusted users where operationally feasible

# Example: restrict Gogs to authenticated internal users via reverse proxy
location /gogs/ {
    allow 10.0.0.0/8;
    deny  all;
    proxy_pass http://127.0.0.1:3000;
    proxy_set_header X-Real-IP $remote_addr;
}