NF20: Improper Authentication
CVE-2022-4874 is a high-severity improper authentication vulnerability in NF20 from Netcomm, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected NF20 versions: R6B025. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 11% chance of exploitation within 30 days, which is in the top 4.03% of all scored CVEs.
EPSS places it among the vulnerabilities most likely to be exploited soon.
What to do
- Update Nf20 Firmware to r6b025 or a later version.
- Update Nf20mesh Firmware to r6b025 or a later version.
- Update Nl1902 Firmware to r6b025 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Netcomm | NF20 | R6B025 | Not stated |
| Netcomm | NF20MESH | R6B025 | Not stated |
| Netcomm | NL1902 | R6B025 | Not stated |
| Netcommwireless | Nf20 Firmware | before r6b025 | r6b025 |
| Netcommwireless | Nf20mesh Firmware | before r6b025 | r6b025 |
| Netcommwireless | Nl1902 Firmware | before r6b025 | r6b025 |
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
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 7.5 | High | CISA (ADP) |
Official description
Authentication bypass in Netcomm router models NF20MESH, NF20, and NL1902 allows an unauthenticated user to access content. In order to serve static content, the application performs a check for the existence of specific characters in the URL (.css, .png etc). If it exists, it performs a "fake login" to give the request an active session to load the file and not redirect to the login page.
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: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- github.com/scarvell/advisories/blob/main/2022_netcomm_nf20mesh_unauth_rce.mdExploit, Third Party Advisory
Other references
Other vulnerabilities in NF20
- 9.8 Critical severity
Recent Improper Authentication vulnerabilities
- 8.1 High severity
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
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