CVE-2025-1677: GitLab CI Pipeline Export DoS Vulnerability

CVE-2025-1677 Overview

A Denial of Service (DoS) vulnerability has been discovered in GitLab CE/EE that allows attackers to disrupt service availability by injecting oversized payloads into CI pipeline exports. This resource exhaustion vulnerability affects multiple versions of both Community Edition and Enterprise Edition, potentially impacting development workflows and continuous integration processes for organizations relying on GitLab infrastructure.

Critical Impact

Attackers can cause service disruption by exploiting the CI pipeline export functionality with maliciously crafted oversized payloads, leading to resource exhaustion and denial of service conditions.

Affected Products

• GitLab Community Edition (CE) all versions up to 17.8.7
• GitLab Enterprise Edition (EE) all versions up to 17.8.7
• GitLab CE/EE versions 17.9 prior to 17.9.6
• GitLab CE/EE versions 17.10 prior to 17.10.4

Discovery Timeline

• 2025-04-10 - CVE-2025-1677 published to NVD
• 2025-08-07 - Last updated in NVD database

Technical Details for CVE-2025-1677

Vulnerability Analysis

This vulnerability is classified under CWE-770 (Allocation of Resources Without Limits or Throttling), which describes a condition where a software application allocates resources in response to requests without implementing proper constraints on the size or number of resources consumed.

In the context of GitLab's CI pipeline export functionality, the application fails to properly validate or limit the size of payloads that can be processed during export operations. This oversight allows an attacker to submit specially crafted requests containing oversized data, forcing the server to consume excessive memory, CPU cycles, or other system resources when processing the malicious export request.

The vulnerability can be exploited remotely over the network without requiring any authentication or user interaction, making it particularly concerning for internet-facing GitLab instances. Successful exploitation results in availability impact but does not compromise the confidentiality or integrity of data stored within the GitLab system.

Root Cause

The root cause of this vulnerability lies in inadequate input validation and resource allocation controls within the CI pipeline export handling code. GitLab's export functionality does not enforce sufficient limits on the payload sizes that can be submitted or processed, allowing attackers to exhaust server resources through resource exhaustion attacks.

The absence of proper throttling mechanisms and size constraints means that when processing export requests, the system will attempt to handle arbitrarily large payloads, leading to memory exhaustion or CPU overload conditions that degrade or completely disrupt service for legitimate users.

Attack Vector

The attack can be executed remotely over the network by any attacker with network access to the vulnerable GitLab instance. The attack leverages the CI pipeline export functionality as the entry point.

An attacker would craft HTTP requests targeting the CI pipeline export endpoints with payloads exceeding normal operational parameters. When the GitLab server attempts to process these oversized exports, it allocates excessive resources without proper bounds checking, eventually leading to service degradation or complete unavailability.

The attack is characterized by low complexity and requires no privileges or user interaction, making it accessible to unauthenticated attackers who can reach the GitLab instance over the network. For detailed technical information about this vulnerability, refer to the GitLab Issue #521117 and HackerOne Report #3004008.

Detection Methods for CVE-2025-1677

Indicators of Compromise

• Unusually large HTTP request payloads targeting CI pipeline export endpoints
• Abnormal memory consumption spikes correlated with export operations
• Increased server response times or timeout errors during CI/CD operations
• Application logs showing export-related processing failures or out-of-memory conditions

Detection Strategies

• Monitor GitLab application logs for anomalous export request patterns and payload sizes
• Implement network-level detection for unusually large requests to GitLab CI pipeline endpoints
• Set up resource monitoring alerts for sudden memory or CPU usage spikes on GitLab servers
• Analyze web server access logs for repeated large POST requests to export-related API endpoints

Monitoring Recommendations

• Configure application performance monitoring (APM) to track resource utilization during export operations
• Implement rate limiting and request size restrictions at the load balancer or reverse proxy level
• Enable GitLab audit logs and monitor for unusual export activity patterns
• Set up automated alerting for service availability degradation or container/process restarts

How to Mitigate CVE-2025-1677

Immediate Actions Required

• Upgrade GitLab CE/EE to version 17.8.7 or later for the 17.8.x branch
• Upgrade GitLab CE/EE to version 17.9.6 or later for the 17.9.x branch
• Upgrade GitLab CE/EE to version 17.10.4 or later for the 17.10.x branch
• Review and restrict network access to GitLab instances to trusted networks where possible

Patch Information

GitLab has released security patches addressing this vulnerability. Organizations should upgrade to the following patched versions:

• 17.8.x branch: Upgrade to version 17.8.7 or later
• 17.9.x branch: Upgrade to version 17.9.6 or later
• 17.10.x branch: Upgrade to version 17.10.4 or later

For detailed patch information and upgrade instructions, refer to the GitLab Issue #521117.

Workarounds

• Implement request size limits at the web application firewall (WAF) or reverse proxy level to restrict payload sizes
• Configure rate limiting on CI pipeline export endpoints to prevent rapid successive exploitation attempts
• Consider temporarily restricting access to CI pipeline export functionality until patches can be applied
• Deploy network segmentation to limit exposure of GitLab instances to untrusted networks

# Example nginx configuration to limit request body size
# Add to nginx.conf or GitLab's nginx configuration

# Limit request body size to prevent oversized payload attacks
client_max_body_size 100m;

# Add rate limiting for export endpoints
limit_req_zone $binary_remote_addr zone=export_limit:10m rate=5r/s;

location ~ /api/v4/projects/.*/export {
    limit_req zone=export_limit burst=10 nodelay;
    # ... existing proxy configuration
}