Multiple Routers: Improper Certificate Validation
CVE-2023-35721 is a high-severity improper certificate validation vulnerability in Multiple Routers from NETGEAR, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected Multiple Routers versions: 1.0.12.120_2.0.83. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1% chance of exploitation within 30 days, higher than 63% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update rax50_firmware to 1.1.15.128 or a later version.
- Read the advisory on kb.netgear.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| NETGEAR | Multiple Routers | 1.0.12.120_2.0.83 | Not stated |
| NETGEAR | rax50_firmware | before 1.1.15.128 | 1.1.15.128 |
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
- AdjacentThe attacker must be on the same local network segment.
- 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:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 3.0 | 8.1 | High | CNA (trendmicro.com) |
Official description
NETGEAR Multiple Routers curl_post Improper Certificate Validation Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to compromise the integrity of downloaded information on affected installations of multiple NETGEAR routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the update functionality, which operates over HTTPS. The issue results from the lack of proper validation of the certificate presented by the server. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root. Was ZDI-CAN-19981.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- zerodayinitiative.com/advisories/ZDI-23-893/Third Party Advisory
Recent Improper Certificate Validation vulnerabilities
- 9.8 Critical severity
- 8.1 High severity
- 8.1 High severity
- 7.5 High severity
- 7.4 High severity
- 9.8 Critical severity
Spotted an error? Tell us.