CVE-2021-40120
Published: 04 November 2021
Summary
CVE-2021-40120 is a medium-severity Improper Input Validation (CWE-20) vulnerability in Cisco Ios Xr. Its CVSS base score is 6.5 (Medium).
Operationally, ranked in the top 34.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-27307
Vulnerability details
A vulnerability in the web-based management interface of certain Cisco Small Business RV Series Routers could allow an authenticated, remote attacker with administrative privileges to inject arbitrary commands into the underlying operating system and execute them using root-level privileges. This…
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vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending malicious input to a specific field in the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying Linux operating system as a user with root-level privileges.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Directly implements checks on information inputs to reject invalid data before processing.
Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.
Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.
Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.
Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.