CVE-2023-38691
matrix-appservice-bridge doesn't verify the sub parameter of an openId token exhange, allowing unauthorized access to provisioning APIs
Severity Score
6.5
*CVSS v3.1
Exploit Likelihood
*EPSS
Affected Versions
*CPE
Public Exploits
0
*Multiple Sources
Exploited in Wild
-
*KEV
Decision
Track
*SSVC
Descriptions
matrix-appservice-bridge provides an API for setting up bridges. Starting in version 4.0.0 and prior to versions 8.1.2 and 9.0.1, a malicious Matrix server can use a foreign user's MXID in an OpenID exchange, allowing a bad actor to impersonate users when using the provisioning API. The library does not check that the servername part of the `sub` parameter (containing the user's *claimed* MXID) is the the same as the servername we are talking to. A malicious actor could spin up a server on any given domain, respond with a `sub` parameter according to the user they want to act as and use the resulting token to perform provisioning requests. Versions 8.1.2 and 9.0.1 contain a patch. As a workaround, disable the provisioning API.
*Credits:
N/A
CVSS Scores
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
* Common Vulnerability Scoring System
SSVC
- Decision:Track
Exploitation
Automatable
Tech. Impact
* Organization's Worst-case Scenario
Timeline
- 2023-07-24 CVE Reserved
- 2023-08-04 CVE Published
- 2024-08-10 EPSS Updated
- 2024-10-07 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-287: Improper Authentication
CAPEC
References (2)
| URL | Tag | Source |
|---|---|---|
| https://github.com/matrix-org/matrix-appservice-bridge/security/advisories/GHSA-vc7j-h8xg-fv5x | Third Party Advisory |
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|---|---|
| https://github.com/matrix-org/matrix-appservice-bridge/commit/4c6723a5e7beda65cdf1ae5dbb882e8beaac8552 | 2023-08-11 |
| URL | Date | SRC |
|---|
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Matrix Search vendor "Matrix" | Matrix-appservice-bridge Search vendor "Matrix" for product "Matrix-appservice-bridge" | >= 4.0.0 < 8.1.2 Search vendor "Matrix" for product "Matrix-appservice-bridge" and version " >= 4.0.0 < 8.1.2" | node.js |
Affected
| ||||||
| Matrix Search vendor "Matrix" | Matrix-appservice-bridge Search vendor "Matrix" for product "Matrix-appservice-bridge" | 9.0.0 Search vendor "Matrix" for product "Matrix-appservice-bridge" and version "9.0.0" | node.js |
Affected
| ||||||