tailscale: Origin Validation Error
CVE-2022-41924 is a critical-severity origin validation error vulnerability in tailscale, with a CVSS 3.1 base score of 9.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected tailscale versions: < 1.32.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.85% chance of exploitation within 30 days, higher than 79% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of tailscale you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.6 | Critical | NVD |
| CVSS 3.0 | 9.6 | Critical | CNA (github.com) |
Official description
A vulnerability identified in the Tailscale Windows client allows a malicious website to reconfigure the Tailscale daemon `tailscaled`, which can then be used to remotely execute code. In the Tailscale Windows client, the local API was bound to a local TCP socket, and communicated with the Windows client GUI in cleartext with no Host header verification. This allowed an attacker-controlled website visited by the node to rebind DNS to an attacker-controlled DNS server, and then make local API requests in the client, including changing the coordination server to an attacker-controlled coordination server. An attacker-controlled coordination server can send malicious URL responses to the client, including pushing executables or installing an SMB share. These allow the attacker to remotely execute code on the node. All Windows clients prior to version v.1.32.3 are affected. If you are running Tailscale on Windows, upgrade to v1.32.3 or later to remediate the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Origin Validation Error
The product does not properly verify that the source of data or communication is valid.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Technical write-ups (may include proof of concept)
- emily.id.au/tailscaleExploit, Technical Description, Third Party Advisory
Other vulnerabilities in tailscale
- 8.0 High severity
- 8.8 High severity
Recent Origin Validation Error vulnerabilities
- 7.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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