Security readout for executives and security teams
Plain-English summary
CVE-2021-1347 affects the web management interface on several Cisco Small Business RV routers. An administrator-authenticated remote attacker could cause full device compromise or force a reboot. The business risk is highest where these routers remain in service and their management interfaces are reachable beyond tightly controlled admin networks.
Executive priority
Treat this as a high-priority edge-device risk if affected routers remain active. The administrator-credential requirement lowers opportunistic exposure, but root-level impact on network infrastructure makes remediation or replacement important.
Technical view
Cisco describes improper validation of user-supplied input in the web-based management interface. A crafted HTTP request from a user with valid administrator credentials can lead to arbitrary code execution as root or a denial-of-service reload. Affected models include RV016, RV042, RV042G, RV082, RV320, and RV325 routers.
Likely exposure
Exposure is most likely in organizations still running the listed Cisco Small Business RV router models, especially where the web-based management interface is reachable remotely or shared administrator credentials are weak, reused, or poorly controlled.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation evidence. Exploitation requires valid administrator credentials, but successful exploitation can provide root-level code execution or cause device reload, making credential compromise materially important.
Researcher notes
The source bundle identifies CWE-121 and CVSS 3.1 score 7.2. Version granularity is not provided in the bundle, so validation should rely on the Cisco advisory and observed device firmware rather than assumed affected ranges.
Mitigation direction
- Review Cisco’s advisory for fixed software or vendor-recommended actions.
- Inventory RV016, RV042, RV042G, RV082, RV320, and RV325 devices.
- Restrict management interface access to trusted administrative networks.
- Remove unnecessary administrator accounts and rotate exposed credentials.
- Monitor affected routers for unexplained reloads or management activity.
Validation and detection
- Confirm whether any listed Cisco RV models remain deployed.
- Record firmware versions and compare them with Cisco advisory guidance.
- Verify management interfaces are not broadly reachable.
- Review administrator account ownership and recent credential changes.
- Check logs or monitoring for unexpected reboots or admin sessions.
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-2021-1347 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.
