CVE-2025-47775
📋 TL;DR
CVE-2025-47775 is a vulnerability in Bullfrog GitHub Action versions before 0.8.4 where using TCP breaks network traffic blocking, allowing DNS exfiltration and potential sandbox bypass. This affects GitHub workflows using vulnerable Bullfrog versions to restrict outbound traffic. Attackers could exfiltrate sensitive data from supposedly restricted workflows.
💻 Affected Systems
- Bullfrog GitHub Action
📦 What is this software?
Bullfrog by Bullfrogsec
⚠️ Risk & Real-World Impact
Worst Case
Complete sandbox bypass allowing exfiltration of sensitive data (secrets, tokens, source code) from GitHub workflows to attacker-controlled infrastructure.
Likely Case
Data exfiltration from workflows containing sensitive information, potentially exposing credentials or proprietary code.
If Mitigated
Limited impact with proper network segmentation and additional security controls beyond Bullfrog.
🎯 Exploit Status
Exploitation requires ability to modify or influence GitHub workflow configurations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.8.4
Vendor Advisory: https://github.com/bullfrogsec/bullfrog/security/advisories/GHSA-m32f-fjw2-37v3
Restart Required: No
Instructions:
1. Update Bullfrog Action reference in GitHub workflow YAML files to v0.8.4 or later. 2. Replace any version references like 'v0.8.3' with 'v0.8.4'. 3. Commit and push changes to trigger workflows with patched version.
🔧 Temporary Workarounds
Disable TCP blocking configuration
allTemporarily remove or disable TCP-based blocking configurations in Bullfrog until patched.
# In workflow YAML, remove or comment out TCP configuration sections
Use alternative network restrictions
allImplement network restrictions at GitHub organization/repository level instead of relying solely on Bullfrog.
🧯 If You Can't Patch
- Implement additional network monitoring for DNS traffic from GitHub workflows
- Restrict workflow permissions to minimum required and audit for sensitive data exposure
🔍 How to Verify
Check if Vulnerable:
Check GitHub workflow YAML files for Bullfrog Action references with versions below 0.8.4.Check Version:
grep -r 'bullfrog' .github/workflows/ --include='*.yml' --include='*.yaml'Verify Fix Applied:
Confirm workflow YAML files reference Bullfrog v0.8.4 or later and test workflow execution with network restrictions.📡 Detection & Monitoring
Log Indicators:
- Unexpected DNS queries from GitHub Actions runners
- Workflow execution failures related to network blocking
Network Indicators:
- DNS traffic to suspicious domains from GitHub IP ranges during workflow execution
SIEM Query:
source="github-actions" AND (protocol="DNS" OR query_type="A" OR query_type="AAAA")🔗 References
- https://github.com/bullfrogsec/bullfrog/commit/ae7744ae4b3a6f8ffc2e49f501e30bf1a43d4671
- https://github.com/bullfrogsec/bullfrog/releases/tag/v0.8.4
- https://github.com/bullfrogsec/bullfrog/security/advisories/GHSA-m32f-fjw2-37v3
- https://github.com/bullfrogsec/bullfrog/security/advisories/GHSA-m32f-fjw2-37v3
