GHSA-3q34-rx83-r6mq — heimdall
Fix: dadrus/heimdall#3209GHSA-3q34-rx83-r6mq is a CWE-35 vulnerability in github.com/dadrus/heimdall. A fix is available for github.com/dadrus/heimdall — see the affected versions and patch details below.
Heimdall has an authorization bypass via path normalization mismatch
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-3q34-rx83-r6mq.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/dadrus/heimdallReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Heimdall performs rule matching on the raw (non-normalized) request path, while downstream components may normalize dot-segments according to RFC 3986, Section 6.2.2.3. This discrepancy can result in heimdall authorizing a request for one path (e.g., /user/../admin, or URL-encoded variants such as /user/%2e%2e/admin or /user/%2e%2e%2fadmin. The latter would require the allow_encoded_slashes option to be set to on or no_decode.) while the downstream ultimately processes a different, normalized path (/admin).
Details
This vulnerability can be exploited by an adversary if rule matching is performed using free (named or unnamed) wildcards without further constraints, as shown in the example snippets below.
id: rule-1
match:
routes:
- path: /user/**
execute: # configured to require authentication and authorization
# ...
id: rule-2
match:
routes:
- path: /public/**
execute: # configured to allow anonymous access
# ...
If an adversary sends a request to /public/../user/whatever, rule-2 will be matched and executed. The downstream service may, however, normalize the request path and interpret it as /user/whatever.
Impact
Bypass of access control policies enforced by heimdall may lead to the following consequences:
- Access to or modification of data that should be restricted
- Invocation of functionality that is expected to require authentication or authorization
- In certain configurations, escalation of privileges depending on the exposed functionality
Workarounds
- Normalize HTTP paths or reject HTTP paths containing relative path expressions in the layers in front of Heimdall - this is good practice anyway. Some proxies do that by default, such as Traefik; others, such as Envoy, require additional configuration (for Envoy see
normalize_path). - Include the ID of the rule expected to be executed in the JWT issued by heimdall and check that value in the consuming project's service.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/dadrus/heimdall | all versions | 0.17.14go get github.com/dadrus/heimdall@v0.17.14 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/dadrus/heimdall, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/dadrus/heimdall to 0.17.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3q34-rx83-r6mq is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-3q34-rx83-r6mq can be triaged on real exposure rather than presence alone.
Tailored to GHSA-3q34-rx83-r6mq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-3q34-rx83-r6mq in your dependencies?
O3 Security finds GHSA-3q34-rx83-r6mq across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.