Security readout for executives and security teams
Plain-English summary
This Cisco issue lets someone who already has administrator credentials abuse the router’s web management interface to run code as root or force a restart. It matters most for organizations still operating listed Small Business RV routers, especially where management access is reachable beyond tightly controlled admin networks.
Executive priority
Treat as high priority for any organization still relying on these routers. The credential requirement lowers broad opportunistic risk, but root-level impact and potential service interruption justify prompt inventory, access restriction, and vendor-guided remediation.
Technical view
CVE-2021-1328 is one of multiple input-validation flaws in the web-based management interface of Cisco Small Business RV016, RV042, RV042G, RV082, RV320, and RV325 routers. Crafted HTTP requests from an authenticated remote administrator can trigger root-level arbitrary code execution or device reload. CVSS 3.1 is 7.2, PR:H.
Likely exposure
Exposure is limited to affected Cisco Small Business RV router models with accessible web management interfaces and valid administrator credentials available to an attacker. Internet-exposed or broadly reachable management interfaces increase practical risk.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. Exploitation requires authenticated administrator access, but successful compromise provides root-level control or denial of service on the router.
Researcher notes
Evidence supports authenticated remote RCE and DoS through improper input validation in the web management interface. The bundle does not include exploit-in-the-wild evidence, workaround specifics, or fixed-version details; rely on Cisco’s advisory for exact remediation status.
Mitigation direction
- Identify whether listed Cisco RV router models are in service.
- Review Cisco’s advisory for fixed software or vendor-supported guidance.
- Restrict web management access to trusted administrator networks.
- Protect and rotate router administrator credentials.
- Monitor for unexpected device reloads and unusual administrator activity.
Validation and detection
- Inventory Cisco RV016, RV042, RV042G, RV082, RV320, and RV325 routers.
- Compare model and firmware status against Cisco’s advisory.
- Verify management interfaces are not broadly reachable.
- Review administrator accounts for stale, shared, or weak credentials.
- Check logs for unexpected reloads or abnormal management requests.
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
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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-2021-1328 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.