A vulnerability in the CLI of stand-alone Cisco IOS XE SD-WAN Software and Cisco SD-WAN…
CVE-2022-20850 is a high-severity improper input validation vulnerability in Cisco SD-WAN Solution from Cisco, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Sd-wan Vbond Orchestrator to 18.4.5 or a later version.
- Update Sd-wan Vmanage to 18.4.5 or a later version.
- Update Sd-wan Vsmart Controller to 18.4.5 or a later version.
- Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco SD-WAN Solution | Not specified in the record | Not stated |
| Cisco | Sd-wan Vbond Orchestrator | before 18.4.5 | 18.4.5 |
| Cisco | Sd-wan Vmanage | before 18.4.5 | 18.4.5 |
| Cisco | Sd-wan Vsmart Controller | before 18.4.5 | 18.4.5 |
| Cisco | iOS Xe Sd-wan | before 16.10.1 | 16.10.1 |
| Cisco | Sd-wan | before 18.4.5 | 18.4.5 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- 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
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.5 | Medium | CNA (cisco.com) |
| CVSS 3.1 | 7.1 | High | NVD |
Official description
A vulnerability in the CLI of stand-alone Cisco IOS XE SD-WAN Software and Cisco SD-WAN Software could allow an authenticated, local attacker to delete arbitrary files from the file system of an affected device. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by injecting arbitrary file path information when using commands in the CLI of an affected device. A successful exploit could allow the attacker to delete arbitrary files from the file system of 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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Cisco SD-WAN Solution
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
Recent Improper Input Validation vulnerabilities
- 7.8 High severity
- 9.8 Critical severity
- 8.2 High severity
- 7.2 High severity
- 9.6 Critical severity
- 6.5 Medium severity
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