Security readout for executives and security teams
Plain-English summary
Cisco identified stored cross-site scripting flaws in the web management interface of several Small Business RV routers. An attacker would need valid administrator credentials and a user to interact with the affected interface. Business risk is mainly administrative-session compromise or browser-based data exposure, not router takeover by itself.
Executive priority
Treat this as a targeted administrative-interface risk, not an internet-wide emergency based on available evidence. Prioritize confirmation of affected routers, vendor guidance review, and management-access hardening, especially for legacy small-office deployments.
Technical view
CVE-2021-1158 covers multiple stored XSS issues caused by insufficient input validation in Cisco RV110W, RV130, RV130W, and RV215W router management interfaces. CVSS 3.1 is 4.8 with network access, low complexity, high privileges, required user interaction, changed scope, and low confidentiality/integrity impact.
Likely exposure
Exposure is limited to organizations still operating the named Cisco Small Business RV routers with active web management access. Risk is higher where administrator accounts are shared, poorly monitored, or the management interface is reachable from broader networks.
Exploitation context
The source bundle does not show CISA KEV listing or other evidence of active exploitation. Exploitation requires valid administrator credentials, crafted HTTP requests, and user interaction with the management interface. No exploit maturity details are provided.
Researcher notes
This is CWE-79 stored XSS in router management UI with PR:H and UI:R. The bundle does not provide fixed version details, workaround language, or proof of exploitation. Avoid assuming affected firmware ranges beyond the named Cisco RV products and vendor advisory.
Mitigation direction
- Identify any RV110W, RV130, RV130W, or RV215W routers in service.
- Check Cisco's advisory for fixed software, support status, and vendor guidance.
- Restrict management interface access to trusted administrators and networks.
- Review and rotate router administrator credentials where exposure is suspected.
- Monitor administrative activity for unexpected configuration or interface changes.
Validation and detection
- Inventory router models and firmware versions against the Cisco advisory.
- Confirm web management interfaces are not exposed beyond intended admin networks.
- Review administrator account lists for unnecessary or shared accounts.
- Check logs for unusual authenticated management activity.
- Document any unsupported devices requiring replacement or compensating controls.
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-2021-1158 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.
