Clash: Improper Authentication
CVE-2024-5732 is a critical-severity improper authentication vulnerability in Clash, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Clash versions: 0.20.0; 0.20.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.89% chance of exploitation within 30 days, higher than 60% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Clash you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
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
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- 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:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.9 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 7.3 | High | CNA (vuldb.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 2.0 | 7.5 | High | CNA (vuldb.com) |
Official description
A vulnerability was found in Clash up to 0.20.1 on Windows. It has been declared as critical. This vulnerability affects unknown code of the component Proxy Port. The manipulation leads to improper authentication. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. It is recommended to change the configuration settings. VDB-267406 is the identifier assigned to this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- vuldb.com/?id.267406Permissions Required, Third Party Advisory, VDB Entry
- vuldb.com/?submit.345469Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- github.com/GTA12138/vul/blob/main/clash%20for%20windows.mdExploit, Third Party Advisory
Other references
- vuldb.com/?ctiid.267406Permissions Required, VDB Entry
Recent Improper Authentication vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 8.1 High severity
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