Security readout for executives and security teams
Plain-English summary
Cisco reports a high-severity flaw in several Small Business RV routers. An attacker with valid administrator credentials could use the web management interface to run code as root or force the router to restart. Business urgency is highest where these routers still protect offices, branches, or remote-access networks.
Executive priority
Treat as a high-priority edge-device issue if these routers are still deployed. The required admin credentials lower broad internet risk, but compromise could give root-level control of network equipment or disrupt connectivity.
Technical view
CVE-2021-1340 affects the web-based management interface of Cisco RV016, RV042, RV042G, RV082, RV320, and RV325 routers. Improper input validation can allow crafted HTTP requests by an authenticated administrator to trigger arbitrary code execution as root or denial of service. The CVSS v3.1 score is 7.2 with high privileges required.
Likely exposure
Exposure is limited to organizations running the listed Cisco Small Business RV router models, especially where the management interface is reachable over networks beyond tightly controlled admin paths. The source bundle does not provide specific affected or fixed firmware versions.
Exploitation context
The bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires valid administrator credentials, but successful exploitation has severe impact because code may run as root or cause device reloads.
Researcher notes
Public evidence in the supplied bundle supports authenticated RCE and DoS through improper input validation in the management interface. CWE-121 is listed. No exploit activity, fixed-version detail, or workaround detail is included beyond the vendor advisory reference.
Mitigation direction
- Check Cisco's advisory for affected and fixed firmware guidance.
- Restrict web management access to trusted administration networks only.
- Review and harden administrator account access and credential practices.
- Disable unnecessary remote management exposure where operationally possible.
- Replace unsupported affected devices if Cisco guidance requires it.
Validation and detection
- Inventory for Cisco RV016, RV042, RV042G, RV082, RV320, and RV325 routers.
- Confirm whether web-based management is enabled and where it is reachable.
- Compare installed firmware and support status against Cisco's advisory.
- Review administrative access records for suspicious logins or unexpected changes.
- Check operational logs for unexplained reloads or management-interface instability.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-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 lookupExecution 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 lookupCVE-2021-1340 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- 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
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.
CVSS vector scores
1 official scoreWe 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.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H1.25.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.2HighVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- 20210203 Cisco Small Business RV Series Routers Management Interface Remote Command Execution and Denial of Service VulnerabilitiesCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
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.