Vulnerability Details : CVE-2021-41130
Extensible Service Proxy, a.k.a. ESP is a proxy which enables API management capabilities for JSON/REST or gRPC API services. ESPv1 can be configured to authenticate a JWT token. Its verified JWT claim is passed to the application by HTTP header "X-Endpoint-API-UserInfo", the application can use it to do authorization. But if there are two "X-Endpoint-API-UserInfo" headers from the client, ESPv1 only replaces the first one, the 2nd one will be passed to the application. An attacker can send two "X-Endpoint-API-UserInfo" headers, the second one with a fake JWT claim. Application may use the fake JWT claim to do the authorization. This impacts following ESPv1 usages: 1) Users have configured ESPv1 to do JWT authentication with Google ID Token as described in the referenced google endpoint document. 2) Users backend application is using the info in the "X-Endpoint-API-UserInfo" header to do the authorization. It has been fixed by v1.58.0. You need to patch it in the following ways: * If your docker image is using tag ":1", needs to re-start the container to pick up the new version. The tag ":1" will automatically point to the latest version. * If your docker image tag pings to a specific minor version, e.g. ":1.57". You need to update it to ":1.58" and re-start the container. There are no workaround for this issue.
Products affected by CVE-2021-41130
- cpe:2.3:a:google:extensible_service_proxy:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-41130
0.11%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 43 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-41130
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
4.9
|
MEDIUM | AV:N/AC:M/Au:S/C:P/I:P/A:N |
6.8
|
4.9
|
NIST | |
5.4
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
2.8
|
2.5
|
NIST | |
6.4
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
3.1
|
2.7
|
GitHub, Inc. |
CWE ids for CVE-2021-41130
-
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.Assigned by:
- nvd@nist.gov (Primary)
- security-advisories@github.com (Secondary)
References for CVE-2021-41130
-
https://cloud.google.com/endpoints/docs/openapi/authenticating-users-google-id
Using Google ID tokens to authenticate usersVendor Advisory
-
https://github.com/cloudendpoints/esp/security/advisories/GHSA-43wx-8qmj-9r9q
X-Endpoint-API-UserInfo can be spoofed. · Advisory · cloudendpoints/esp · GitHubThird Party Advisory
-
https://github.com/cloudendpoints/esp/commit/e310c4f91d229a072507f80c73811489b4cdff27
Remove X-Endpoint-API-UserInfo for all header occurrences. (#845) · cloudendpoints/esp@e310c4f · GitHubPatch;Third Party Advisory
-
https://github.com/cloudendpoints/esp/releases/tag/v1.58.0
Release Endpoints Runtime Release 1.58.0 · cloudendpoints/esp · GitHubThird Party Advisory
Jump to