Headline
GHSA-hq8w-9w8w-pmx7: WireMock Controlled Server Side Request Forgery vulnerability through URL
Impact
WireMock can be configured to only permit proxying (and therefore recording) to certain addresses. This is achieved via a list of allowed address rules and a list of denied address rules, where the allowed list is evaluated first. Documentation.
Until WireMock Webhooks Extension 3.0.0-beta-15, the filtering of target addresses from the proxy mode DID NOT work for Webhooks, so the users were potentially vulnerable regardless of the limitProxyTargets settings.
Via the WireMock webhooks configuration, POST requests from a webhook might be forwarded to an arbitrary service reachable from WireMock’s instance. For example, If someone is running the WireMock docker Container inside a private cluster, they can trigger internal POST requests against unsecured APIs or even against secure ones by passing a token, discovered using another exploit, via authentication headers.
Affected components
- WireMock Webhooks Extension 2.x versions until 2.35.1 (security patch)
- WireMock 3.x version until 3.0.3 (security patch)
- All versions of WireMock Studio (discontinued). This distribution bundles the WireMock Webhooks Extension and activates it by default
Patches and Mitigation
- For WireMock 2.x and 3.x - upgrade to the versions with the security patches
- Setup network restrictions similarly to https://wiremock.org/docs/configuration/#preventing-proxying-to-and-recording-from-specific-target-addresses
- For WireMock Studio: Stop using discontinued WireMock Studio, migrate to other distributions. The vendor of WireMock Studio recommends migration to WireMock Cloud
NOTE: It was confirmed that WireMock Cloud does not expose sensitive internal APIs and hence not vulnerable to the issue. No action is needed if you use this SaaS distribution.
Workarounds
- Use external firewall rules to define the list of permitted destinations
References
Credits
- @W0rty for reporting CVE-2023-39967 in WireMock Studio
- WireMock Inc. team for discovering similar exploits in Webhooks and the risk in the Proxy mode defaults for WireMock
Impact
WireMock can be configured to only permit proxying (and therefore recording) to certain addresses. This is achieved via a list of allowed address rules and a list of denied address rules, where the allowed list is evaluated first. Documentation.
Until WireMock Webhooks Extension 3.0.0-beta-15, the filtering of target addresses from the proxy mode DID NOT work for Webhooks, so the users were potentially vulnerable regardless of the limitProxyTargets settings.
Via the WireMock webhooks configuration, POST requests from a webhook might be forwarded to an arbitrary service reachable from WireMock’s instance. For example, If someone is running the WireMock docker Container inside a private cluster, they can trigger internal POST requests against unsecured APIs or even against secure ones by passing a token, discovered using another exploit, via authentication headers.
Affected components
- WireMock Webhooks Extension 2.x versions until 2.35.1 (security patch)
- WireMock 3.x version until 3.0.3 (security patch)
- All versions of WireMock Studio (discontinued). This distribution bundles the WireMock Webhooks Extension and activates it by default
Patches and Mitigation
- For WireMock 2.x and 3.x - upgrade to the versions with the security patches
- Setup network restrictions similarly to https://wiremock.org/docs/configuration/#preventing-proxying-to-and-recording-from-specific-target-addresses
- For WireMock Studio: Stop using discontinued WireMock Studio, migrate to other distributions. The vendor of WireMock Studio recommends migration to WireMock Cloud
NOTE: It was confirmed that WireMock Cloud does not expose sensitive internal APIs and hence not vulnerable to the issue. No action is needed if you use this SaaS distribution.
Workarounds
- Use external firewall rules to define the list of permitted destinations
References
- CVE-2023-39967
- Preventing proxying to and recording from specific target addresses
Credits
- @W0rty for reporting CVE-2023-39967 in WireMock Studio
- WireMock Inc. team for discovering similar exploits in Webhooks and the risk in the Proxy mode defaults for WireMock
References
- GHSA-hq8w-9w8w-pmx7
- https://github.com/wiremock/wiremock/releases/tag/2.35.1
- https://github.com/wiremock/wiremock/releases/tag/3.0.3
Related news
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 ...
WireMock is a tool for mocking HTTP services. WireMock can be configured to only permit proxying (and therefore recording) to certain addresses. This is achieved via a list of allowed address rules and a list of denied address rules, where the allowed list is evaluated first. Until WireMock Webhooks Extension 3.0.0-beta-15, the filtering of target addresses from the proxy mode DID NOT work for Webhooks, so the users were potentially vulnerable regardless of the `limitProxyTargets` settings. Via the WireMock webhooks configuration, POST requests from a webhook might be forwarded to an arbitrary service reachable from WireMock’s instance. For example, If someone is running the WireMock docker Container inside a private cluster, they can trigger internal POST requests against unsecured APIs or even against secure ones by passing a token, discovered using another exploit, via authentication headers. This issue has been addressed in versions 2.35.1 and 3.0.3 of wiremock. Wiremock studio h...