Security readout for executives and security teams
Plain-English summary
CVE-2021-1326 affects Cisco Small Business RV-series routers. If an attacker already has valid administrator credentials, they may execute code as root or force the router to restart. This is high impact, but the administrator credential requirement limits opportunistic exposure compared with unauthenticated internet attacks.
Executive priority
Treat this as a high-priority network-edge hygiene issue, especially for small-office or branch routers. The main business risk is attacker control of routing infrastructure or outage, but urgency depends on whether admin interfaces are exposed and whether credentials are well protected.
Technical view
The issue is in the web-based management interface of Cisco RV016, RV042, RV042G, RV082, RV320, and RV325 routers. Improper validation of user-supplied input can allow crafted HTTP requests by an authenticated remote administrator to trigger root-level code execution or denial of service. CVSS v3.1 is 7.2 high with PR:H.
Likely exposure
Exposure is likely limited to environments running the named Cisco Small Business RV routers with reachable web management interfaces and valid administrator accounts available to an attacker. The source bundle does not provide affected firmware version ranges.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. Exploitation requires valid administrator credentials and network access to the router management interface, then abuse of crafted HTTP requests. No unauthenticated exploitation is supported by the bundle.
Researcher notes
The bundle identifies CWE-121 and input validation failures in the management interface, but does not include firmware ranges, fixed versions, or exploit telemetry. Analysis should focus on asset confirmation, management-plane reachability, administrator credential control, and Cisco advisory mapping.
Mitigation direction
- Inventory the named Cisco RV router models in use.
- Check Cisco’s advisory for official fixed firmware or mitigation guidance.
- Apply Cisco-recommended updates after confirming affected firmware.
- Restrict management-interface access to authorized administrative networks.
- Review administrator accounts and credentials on exposed devices.
Validation and detection
- Confirm whether RV016, RV042, RV042G, RV082, RV320, or RV325 devices are deployed.
- Identify firmware versions and compare them with Cisco advisory guidance.
- Verify web management interfaces are not broadly reachable.
- Review router administrator accounts for stale or shared credentials.
- Check logs for unexpected administrative access or device reloads.
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-2021-1326 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.