Know every vulnerabilitybefore it knows you.
DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.
GHSA-qrwj-vh9x-gw5v
No affected components available
Summary
agentConn.apiClient() used the default redirect behavior of http.Client while its custom transport dialed the host from the request URL as long as the port was the workspace agent HTTP API port (4). Agent tailnet IPs are deterministic from agent UUIDs, so a malicious workspace agent could return a redirect to another agent's tailnet IP and cause the control-plane client to send the follow-up workspace agent API request to the victim agent instead of the intended agent.
Redirects that preserve the method and body, such as HTTP 307 and 308, allow replay of write and process-start requests. HTTP 301, 302 and 303 redirects only convert POST requests to GET requests, so they are sufficient to demonstrate redirected reads but not write or command-execution primitives.
Impact
An authenticated user with a running workspace and control of a modified workspace agent can redirect workspace agent API requests made to their agent toward another online workspace agent reachable on the tailnet. If the attacker knows the victim agent UUID, they can derive the victim's tailnet IP and target the victim's file APIs to read or write files as the victim workspace user.
In affected versions that expose the workspace agent process API, the same primitive can be chained to command execution as the victim workspace user by writing a payload through the redirected file API and then redirecting a process-start request to execute it. This crosses workspace and tenant boundaries.
Patches
The fix disables automatic redirect following for workspace agent API clients and pins all workspace agent API dials to the intended agent's deterministic tailnet address. Requests whose URL host does not match the intended agent are rejected instead of being dialed.
The fix was backported to all supported release lines:
| Release line | Patched version | |---|---| | 2.34 | v2.34.4 | | 2.33 | v2.33.10 | | 2.32 | v2.32.9 | | 2.29 (ESR) | v2.29.19 |
Workarounds
None. Upgrading is required.
Resources
- Fix: #26600
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a low impact on the availability of the system.
Exploitation activity has been observed. Apply available patches or mitigations urgently.
Probability that this vulnerability will be exploited in the wild within the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
Browse More
Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.
Checkout DevGuard