GHSA-pmxq-pj47-j8j4
LOWDomain restrictions bypass via DNS Rebinding in WireMock and WireMock Studio webhooks, proxy and recorder modes
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.
Blast Radius
org.wiremock:wiremock-standalone☕org.wiremock:wiremock☕com.github.tomakehurst:wiremock-jre8☕com.github.tomakehurst:wiremock-jre8-standalone🐍wiremockReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Impact
The proxy mode of WireMock, can be protected by the network restrictions configuration, as documented in Preventing proxying to and recording from specific target addresses. These restrictions can be configured using the domain names, and in such a case the configuration is vulnerable to the DNS rebinding attacks. A similar patch was applied in WireMock 3.0.0-beta-15 for the WireMock Webhook Extensions.
The root cause of the attack is a defect in the logic which allows for a race condition triggered by a DNS server whose address expires in between the initial validation and the outbound network request that might go to a domain that was supposed to be prohibited. Control over a DNS service is required to exploit this attack, so it has high execution complexity and limited impact.
Affected versions
- WireMock 3,x until 3.0.3 (security patch), on default settings in environments with access to the network
- WireMock 2.x until 2.35.1 (security patch), on default settings in environments with access to the network
- Python WireMock until 2.6.1
- WireMock Studio - all versions, this proprietary product was discontinued in 2022
Patches
- WireMock 3.0.3 + the 3.0.3-1 Docker image
- WireMock 2.35.1 + the 2.35.1-1 Docker image - backport to WireMock 2.x
- Python WireMock 2.6.1
Workarounds
For WireMock:
- Option 1: Configure WireMock to use IP addresses instead of the domain names in the outbound URLs subject to DNS rebinding
- Option 2: Use external firewall rules to define the list of permitted destinations
For WireMock Studio: N/A. Switch to another distribution, there will be no fix provided. The vendor of former WireMock Studio recommends migration to WireMock Cloud
References
- CVE-2023-41327 - Related issue in the WireMock Webhooks Extension
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.wiremock:wiremock-standalone | all versions | 3.0.3 |
| ☕Maven | org.wiremock:wiremock | all versions | 3.0.3 |
| ☕Maven | com.github.tomakehurst:wiremock-jre8 | all versions | 2.35.1 |
| ☕Maven | com.github.tomakehurst:wiremock-jre8-standalone | all versions | 2.35.1 |
| 🐍PyPI | wiremock | all versions | 2.6.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.wiremock:wiremock-standalone. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.wiremock:wiremock-standalone to 3.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pmxq-pj47-j8j4 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 pinpoints whether GHSA-pmxq-pj47-j8j4 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-pmxq-pj47-j8j4. 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-pmxq-pj47-j8j4 in your dependencies?
O3 detects GHSA-pmxq-pj47-j8j4 across Maven, PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.