Security readout for executives and security teams
Plain-English summary
CVE-2021-1337 affects Cisco Small Business RV-series routers. An attacker with valid administrator credentials could abuse the web management interface to run code as root or crash the device. The business risk is highest where these routers are still in use and their management interface is reachable beyond tightly controlled admin networks.
Executive priority
Treat this as a high-priority edge-device risk if affected routers are present. The credential requirement lowers mass-exploitation likelihood, but root-level impact on network equipment can affect confidentiality, integrity, availability, and incident response visibility.
Technical view
The vulnerability is improper validation of user-supplied input in the web-based management interface of Cisco RV016, RV042, RV042G, RV082, RV320, and RV325 routers. It is network-reachable, low-complexity, requires high privileges, and can lead to root-level code execution or denial of service. CVSS v3.1 score is 7.2.
Likely exposure
Exposure is likely limited to organizations still running the named Cisco Small Business RV routers. Practical risk rises when administrator credentials are weak, shared, compromised, or when the management interface is reachable from untrusted networks.
Exploitation context
The source bundle does not indicate active exploitation, and this CVE is not marked KEV. Exploitation requires valid administrator credentials, but successful abuse could give root-level control of the router or cause unexpected reloads.
Researcher notes
Do not assess this as unauthenticated RCE. The key exposure questions are device presence, firmware status, management-plane reachability, and administrator credential control. The bundle does not provide fixed-version details, so remediation should be anchored to Cisco’s advisory.
Mitigation direction
- Identify whether any named Cisco RV-series routers remain deployed.
- Check Cisco’s advisory for fixed firmware, workarounds, or product-specific guidance.
- Restrict management interface access to trusted administrative networks only.
- Review and rotate administrator credentials for affected devices.
- Replace unsupported or unpatchable devices where vendor guidance cannot be applied.
Validation and detection
- Inventory RV016, RV042, RV042G, RV082, RV320, and RV325 devices.
- Confirm firmware and model status against Cisco’s advisory.
- Verify the web management interface is not internet-exposed.
- Review administrator accounts for stale, shared, or weak credentials.
- Check device logs for unexpected reloads or unusual administrative access.
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-2021-1337 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.