Cyber Resilience

CVE-2021-1473

Command Injection in Cisco Rv340 Firmware ≤ 1.0.03.21

Published
08 April 2021
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.64 99.1th percentile
Risk Priority 80 floored blend · peak EPSS

Summary

CVE-2021-1473 is a medium-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Cisco Rv340 Firmware. Its CVSS base score is 5.3 (Medium).

Operationally, ranked in the top 0.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Multiple vulnerabilities exist in the web-based management interface of Cisco Small Business RV Series Routers. A remote attacker could execute arbitrary commands or bypass authentication and upload files on an affected device. For more information about these vulnerabilities, see the…

more

Details section of this advisory.

CWE(s)

Related Threats

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1190 Exploit Public-Facing Application Initial Accessconfidence: HIGH
Remote command execution via the web management interface directly enables exploitation of a public-facing application.
T1059.004 Unix Shell Executionconfidence: HIGH
Arbitrary command execution on the router OS maps to Unix shell command interpreter usage.
T1505.003 Web Shell Persistenceconfidence: MEDIUM
File upload capability on the web interface can facilitate deployment of a web shell for persistent access.
T1078 Valid Accounts Stealthconfidence: MEDIUM
Bypassing authentication allows use of valid (or impersonated) accounts on the device.
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2022-20708Same product: Cisco Rv340
CVE-2023-20007Same product: Cisco Rv340
CVE-2021-1472Same product: Cisco Rv340
CVE-2017-6738Same vendor: Cisco
CVE-2017-6737Same vendor: Cisco
CVE-2023-20163Same vendor: Cisco
CVE-2017-6736Same vendor: Cisco
CVE-2024-20424Same vendor: Cisco
CVE-2024-20458Same vendor: Cisco
CVE-2017-6742Same vendor: Cisco

Affected Assets

cisco
rv340 firmware
≤ 1.0.03.21
cisco
rv340w firmware
≤ 1.0.03.21
cisco
rv345 firmware
≤ 1.0.03.21
cisco
rv345p firmware
≤ 1.0.03.21

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V17.3.2
  • V1.2.5
  • V1.2.8
  • V15.2.5

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.

addresses: CWE-78 CWE-119

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.

addresses: CWE-119

Ongoing control assessments and code testing (static/dynamic analysis, fuzzing) surface memory buffer restriction failures, which are then remediated before release.

addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

addresses: CWE-119

Memory protections (e.g., W^X, ASLR) make exploitation of buffer-boundary violations far harder to turn into code execution.

addresses: CWE-119

Detects exploitation attempts that produce memory corruption, crashes, or anomalous behavior.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis directly surface buffer-boundary flaws.

ID.RA-08 partial match
prevents

Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.

PR.AT-02 partial match
prevents

Developer training on secure coding reduces introduction of memory-buffer errors.

PR.PS-02 partial match
prevents

Patching replaces vulnerable code containing buffer-boundary defects.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.

prevents

Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.

prevents

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

prevents

Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.

prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

References