WN531G3: Authentication Bypass by Capture-replay
CVE-2022-40621 is a high-severity authentication bypass by capture-replay vulnerability in WN531G3 from WAVLINK, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected WN531G3 versions: M31G3.V5030.200325 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.85% chance of exploitation within 30 days, higher than 59% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of WN531G3 you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| WAVLINK | WN531G3 | M31G3.V5030.200325 and earlier | Not stated |
| WAVLINK | Wn531g3 Firmware | m31g3.v5030.200325 and earlier | Not stated |
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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- 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:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
Because the WAVLINK Quantum D4G (WN531G3) running firmware version M31G3.V5030.200325 and earlier communicates over HTTP and not HTTPS, and because the hashing mechanism does not rely on a server-supplied key, it is possible for an attacker with sufficient network access to capture the hashed password of a logged on user and use it in a classic Pass-the-Hash style attack.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authentication Bypass by Capture-replay
A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).
How developers prevent this class of flaw
- Utilize some sequence or time stamping functionality along with a checksum which takes this into account in order to ensure that messages can be parsed only once.
- Since any attacker who can listen to traffic can see sequence numbers, it is necessary to sign messages with some kind of cryptography to ensure that sequence numbers are not simply doctored along with content.
More Authentication Bypass by Capture-replay vulnerabilities (CWE-294)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- malbytes.net/2022/07/wavlink-quantum-d4g-zero-day-part-01.htmlExploit, Third Party Advisory
Other vulnerabilities in WN531G3
- 8.8 High severity
- 8.8 High severity
Recent Authentication Bypass by Capture-replay vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
- 8.8 High severity
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