CISA Flags Active Exploitation: Critical Gogs Path Traversal (CVE-2025-8110) Added to KEV

Product: Gogs (self-hosted Git service)
CVE ID: CVE-2025-8110
CVSS v3.1 Score: 9.8 / 10
Severity: Critical
Exploitability: High (low attack complexity, minimal prerequisites)
Exploit Availability: Public proof-of-concept exists; active exploitation confirmed
KEV Status: Added to CISA Known Exploited Vulnerabilities (KEV) Catalog
Impact: Arbitrary file read, credential disclosure, CI/CD compromise, potential remote code execution

Executive Summary

A critical path traversal vulnerability in Gogs allows attackers to access files outside of intended Git repository directories. This flaw enables unauthorized reading of sensitive system and application files and has already been observed being exploited in real-world environments.

Because Gogs is frequently deployed as an internet-facing service and deeply integrated into development pipelines, successful exploitation can expose source code, secrets, credentials, and in certain configurations, lead to full system compromise.

Technical Overview

What is the vulnerability?

Gogs improperly handles user-controlled file paths in specific repository and file-related endpoints. While some validation exists, it fails to fully prevent directory traversal when encoded or nested traversal sequences are used.

The application resolves file paths after decoding user input but does not consistently enforce that the resolved path remains within the repository root directory. This allows attackers to escape the repository boundary and access arbitrary files on the underlying host.

Why this is dangerous

Once attackers gain arbitrary file read capability, they can directly access:

custom/conf/app.ini (contains database credentials, secrets, and admin settings)
SSH private keys used by the Gogs service
Environment variables and CI secrets stored as files
Source code of unrelated repositories
System files that assist in reconnaissance or privilege escalation

In many real deployments, these files provide enough access to pivot into databases, cloud services, or CI/CD runners, effectively escalating a file disclosure flaw into full infrastructure compromise.

Root Cause Analysis

This issue stems from a trust boundary violation rather than a single missing check:

URL decoding occurs before final path normalization
Double-encoded traversal strings bypass validation logic
Canonical path checks are inconsistently enforced
Repository isolation relies on string comparison instead of filesystem-level enforcement

Because of this, traversal payloads can be interpreted as legitimate repository paths after decoding and normalization.

Exploitation Flow

Step 1: Path Traversal Injection

The attacker sends crafted HTTP requests containing traversal sequences—often encoded—to repository endpoints that serve files.

Step 2: Arbitrary File Read

The server responds with files located outside the repository directory, frequently returning HTTP 200 responses.

Step 3: Credential Extraction

Sensitive configuration files such as app.ini are parsed to obtain:

Database usernames and passwords
Secret keys
OAuth tokens
Admin account settings

Step 4: Escalation and Lateral Movement

Depending on the environment:

Admin access to Gogs is obtained
Databases are accessed directly
CI/CD secrets are reused
SSH access is established
Additional internal systems are compromised

Payload Patterns (Education & Detection Purpose)

These examples are provided strictly for defensive and detection purposes.

../../../../etc/passwd
..%2f..%2f..%2f..%2fetc%2fpasswd
..%252f..%252f..%252fcustom%252fconf%252fapp.ini

Frequently targeted files include:

/etc/passwd
custom/conf/app.ini
.ssh/id_rsa
.env
CI pipeline configuration files
Mounted secrets in containerized deployments

Detection & Monitoring Strategy

Log Sources That Matter

Gogs application logs
Nginx / Apache access logs
Reverse proxy or load balancer logs
Web Application Firewall logs
Endpoint security or file integrity logs
Azure Application Gateway / Front Door logs (if applicable)

Common Behavioral Red Flags

Requests containing traversal sequences followed by HTTP 200 responses
Access to configuration files outside normal admin workflows
Sudden increase in file reads by the Gogs process
Admin logins from IPs previously only making unauthenticated requests
CI pipeline anomalies shortly after suspicious file access

Microsoft Sentinel Detection Rules (KQL)

Detect Traversal Attempts Against Gogs

CommonSecurityLog
| where RequestURL has_any ("../", "%2e%2e%2f", "%252e%252e%252f")
| where DeviceProduct has "Gogs" or RequestURL has "/gogs/"
| summarize AttemptCount=count() by SourceIP, RequestURL, bin(TimeGenerated, 5m)

Successful Access to Sensitive Files

AzureDiagnostics
| where requestUri_s has_any ("app.ini", "id_rsa", ".env", "/etc/passwd")
| where requestUri_s has_any ("../", "%2e%2e")
| where httpStatus_d == 200
| project TimeGenerated, clientIP_s, requestUri_s

Enumeration or Brute Traversal Behavior

CommonSecurityLog
| where RequestURL has_any ("../", "%2e%2e")
| summarize Attempts=count() by SourceIP, bin(TimeGenerated, 10m)
| where Attempts > 15

Correlate Traversal with Successful Authentication

SigninLogs
| where ResultType == 0
| where IPAddress in (
    CommonSecurityLog
    | where RequestURL has_any ("../", "%2e%2e")
    | project SourceIP
)

Indicators of Compromise (IOCs)

Network Indicators

Repeated GET requests with encoded traversal strings
Access to non-repository paths via repository endpoints
Source IPs iterating through multiple encoding variations

Host & Application Indicators

Unexpected reads of custom/conf/app.ini
Gogs service accessing .ssh directories
File access events outside repository storage paths

Behavioral Indicators

Admin or database logins shortly after file disclosure
Credential rotation events triggered unexpectedly
CI/CD pipeline secrets being accessed or reused

MITRE ATT&CK Mapping

Tactic	Technique ID	Description
Initial Access	T1006	Path traversal
Credential Access	T1552	Credentials from files
Discovery	T1083	File and directory discovery
Privilege Escalation	T1068	Exploiting misconfiguration
Lateral Movement	T1021	Using valid credentials

Mitigation & Remediation Guidance

Immediate Defensive Actions

Apply the official Gogs patch immediately
Restrict public access to Gogs where possible
Rotate all secrets stored in app.ini
Audit SSH keys, API tokens, and CI secrets
Place Gogs behind a WAF or hardened reverse proxy
Review historical logs for exploitation attempts
Treat exposed systems as potentially compromised
Rebuild CI runners or hosts if credential exposure is confirmed

Official Patch

Official Gogs Security Fix:
https://github.com/gogs/gogs/releases

Upgrade to the latest stable version addressing CVE-2025-8110.
Avoid unofficial patches or forks unless formally validated.

Why This CVE Deserves Immediate Attention

Actively exploited in the wild
Simple to exploit and easy to automate
Exposes source code, secrets, and infrastructure credentials
Frequently deployed with high trust and low visibility
Often integrated into CI/CD pipelines with elevated privileges

Final Takeaway

CVE-2025-8110 is not a theoretical flaw—it is a practical, high-impact vulnerability with real operational consequences. Any organization running Gogs should assume exposure if the service was internet-facing and unpatched.