A vulnerability in the web-based management interface of Cisco Small Business RV016, RV042…
CVE-2023-20026 is a high-severity improper input validation vulnerability in Cisco Small Business RV Series Router Firmware from Cisco, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected Cisco Small Business RV Series Router Firmware versions: 1.0.00.29; 1.0.00.33; 1.0.01.16, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.3% chance of exploitation within 30 days, higher than 71% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Cisco Small Business RV Series Router Firmware you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco Small Business RV Series Router Firmware | 1.0.00.29; 1.0.00.33; 1.0.01.16; 1.0.01.17; 1.0.01.18; 1.0.01.20; 1.0.02.16; 1.0.03.15; and 32 more ranges | Not stated |
| Cisco | Rv016 Firmware | Not specified in the record | Not stated |
| Cisco | Rv042 Firmware | Not specified in the record | Not stated |
| Cisco | Rv042g Firmware | Not specified in the record | Not stated |
| Cisco | Rv082 Firmware | Not specified in the record | 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
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- 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:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.5 | Medium | CNA (cisco.com) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
A vulnerability in the web-based management interface of Cisco Small Business RV016, RV042, RV042G, RV082, RV320 and RV325 Routers could allow an authenticated, remote attacker to execute arbitrary commands on an affected device. This vulnerability is due to improper validation of user input within incoming HTTP packets. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web-based management interface. A successful exploit could allow the attacker to gain root-level privileges and access unauthorized data. To exploit this vulnerability, an attacker would need to have valid administrative credentials on the affected device.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Cisco Small Business RV Series Router Firmware
- 9.1 Critical severity
- 9.1 Critical severity
- 9.1 Critical severity
- 9.1 Critical severity
- 7.2 High severity
- 8.8 High severity
Recent Improper Input Validation vulnerabilities
- 7.2 High severity
- 8.6 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.5 High severity
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