Security readout for executives and security teams
Plain-English summary
This Cisco router issue affects the web management interface. An attacker already holding administrator credentials could store script content that runs in another interface user’s browser. Business risk is mainly credential/session exposure or unauthorized interface actions, not direct router takeover from the internet without admin access.
Executive priority
Treat as a moderate-priority network-edge hygiene issue. It is not reported as actively exploited in the supplied evidence, but affected routers are perimeter-adjacent assets and the products are older small-business devices, so ownership, firmware status, and replacement plans should be verified.
Technical view
CVE-2021-1151 covers multiple stored XSS flaws in Cisco Small Business RV110W, RV130, RV130W, and RV215W routers. Cisco attributes the issue to insufficient input validation in the web-based management interface. Exploitation requires valid administrator credentials and user interaction, with CVSS 3.1 score 4.8, CWE-79.
Likely exposure
Exposure is limited to organizations still operating the listed Cisco Small Business RV router models with reachable web management interfaces. Risk increases where administrator credentials are shared, weak, reused, or where management access is available from broad networks.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. Exploitation requires authenticated administrator access and a victim using the affected management interface, so this is more plausible after credential compromise or insider misuse than as a standalone unauthenticated attack.
Researcher notes
Evidence is limited to the CVE record and Cisco advisory reference. The key constraints are PR:H and UI:R: valid administrator credentials and interaction with the management interface are required. Avoid assuming unauthenticated exploitability, active exploitation, or a specific fixed version unless confirmed in Cisco guidance.
Mitigation direction
- Review Cisco’s advisory for affected firmware status and vendor remediation guidance.
- Restrict management interface access to trusted administrative networks where feasible.
- Ensure router administrator credentials are unique, strong, and limited to authorized staff.
- Remove or disable unnecessary administrator accounts on affected devices.
- Monitor administrative interface activity for unexpected changes or suspicious requests.
Validation and detection
- Inventory Cisco RV110W, RV130, RV130W, and RV215W devices in use.
- Confirm whether web-based management interfaces are reachable from untrusted networks.
- Review firmware versions against Cisco’s advisory and vendor guidance.
- Audit administrator accounts and recent management interface activity.
- Document whether affected devices remain supported or require replacement planning.
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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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 lookupCVE-2021-1151 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
- Medium
- CVSS
- 4.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
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:R/S:C/C:L/I:L/A:N1.72.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.8MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- 20210113 Cisco Small Business RV110W, RV130, RV130W, and RV215W Routers Management Interface Stored Cross-Site Scripting 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.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.