LiveActive security incident?Get immediate response
CVE Record

CVE-2021-1320: Cisco Small Business RV Series Routers Management Interface Remote Command Execution and Denial of Service Vulnerabilities

Multiple vulnerabilities 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 code or cause an affected device to restart unexpectedly. These vulnerabilities are due to improper validation of user-supplied input in the web-based management interface. An attacker could exploit these vulnerabilities by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system or cause the device to reload, resulting in a denial of service (DoS) condition. To exploit these vulnerabilities, an attacker would need to have valid administrator credentials on the affected device.

HighCVSS 7.2Not KEV-listedUpdated
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

This flaw affects Cisco Small Business RV-series routers. An attacker who already has valid administrator credentials could abuse the web management interface to run code as root or force the router to restart. That can expose network edge infrastructure to full device compromise or downtime.

Executive priority

Treat this as a high-priority edge-device issue if affected routers remain in service. It requires admin credentials, but successful exploitation could give root-level control of a network gateway or cause outages.

Technical view

CVE-2021-1320 is an authenticated remote command execution and denial-of-service issue in the web-based management interface. Cisco attributes it to improper validation of user-supplied input. CVSS v3.1 is 7.2 with network attack vector, low complexity, high privileges required, and high confidentiality, integrity, and availability impact.

Likely exposure

Exposure is most likely where Cisco RV016, RV042, RV042G, RV082, RV320, or RV325 routers are deployed and their web management interface is reachable by administrator accounts. The source bundle does not specify affected firmware versions.

Exploitation context

The cited data says exploitation requires valid administrator credentials. The source bundle does not show CISA KEV listing or other evidence of active exploitation. Business risk increases if admin credentials are shared, reused, weak, or the management interface is reachable from untrusted networks.

Researcher notes

Important gaps remain: the bundle lists affected product families but not specific firmware ranges or fixed versions. Validation should focus on device inventory, management-plane exposure, credential hygiene, and Cisco advisory mapping rather than unauthenticated exploit assumptions.

Mitigation direction

  • Review Cisco advisory for affected firmware and supported fixed releases.
  • Apply vendor-supported firmware updates where Cisco identifies them.
  • Restrict management interface access to trusted administrative networks.
  • Audit and rotate router administrator credentials.
  • Disable remote management if it is not operationally required.
  • Monitor for unexpected router reloads or administrative activity.

Validation and detection

  • Inventory Cisco RV016, RV042, RV042G, RV082, RV320, and RV325 devices.
  • Confirm firmware versions against Cisco advisory guidance.
  • Verify management interfaces are not exposed to untrusted networks.
  • Review administrator accounts for unnecessary, shared, or stale access.
  • Check logs for unexpected reboots or suspicious admin sessions.
Prepared
Confidence
medium
Sources
3

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-121: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2021-1320 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.2 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
2Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.2CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H1.25.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

7.2High
CVSS 3.1 vector shape for CVE-2021-1320Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone
Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
CiscoCisco Small Business RV Series Router Firmwaren/aListed
Weakness

CWE details

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-121 · source CWE mapping

Stack-based Buffer Overflow

Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.