Security readout for executives and security teams
Plain-English summary
This CVE affects Cisco Small Business RV110W, RV130, RV130W, and RV215W routers. An attacker with valid administrator credentials could store malicious script in the web management interface, causing it to run in another user’s browser. Business impact is mainly account/session data exposure or unauthorized interface actions, not router outage.
Executive priority
Treat this as a moderate-priority hygiene issue. It is not known to be actively exploited from the supplied evidence, but affected edge routers should be reviewed because management interface compromise can support broader network risk.
Technical view
CVE-2021-1157 is a stored XSS issue in the web-based management interface caused by insufficient input validation. It is network-reachable but requires high privileges and user interaction. CVSS 3.1 is 4.8 with low confidentiality and integrity impact and no availability impact. The supplied sources do not provide affected firmware ranges or fixed versions.
Likely exposure
Exposure is limited to organizations still operating Cisco Small Business RV110W, RV130, RV130W, or RV215W routers with accessible management interfaces. Risk increases if administration is reachable from untrusted networks or shared among multiple admins.
Exploitation context
The provided sources do not state active exploitation, and KEV is false. Exploitation requires valid administrator credentials and interaction by a user of the management interface, making opportunistic exploitation less likely than unauthenticated router flaws.
Researcher notes
Key constraints are high privileges and user interaction. The source bundle identifies CWE-79 and affected product families, but not exact firmware ranges, patches, or workarounds. Avoid assuming exploit availability or fixed versions beyond Cisco’s advisory.
Mitigation direction
- Review Cisco’s advisory for fixed firmware and device-specific guidance.
- Apply vendor-provided firmware updates where available.
- Restrict management access to trusted admin networks or VPN.
- Disable remote management when not required.
- Limit router administrator accounts to necessary personnel only.
- Monitor for unexpected configuration changes or administrator activity.
Validation and detection
- Inventory RV110W, RV130, RV130W, and RV215W devices.
- Confirm whether their web management interfaces are reachable externally.
- Record firmware versions and compare them with Cisco guidance.
- Review administrator account lists for unnecessary or stale access.
- Check management logs for unusual configuration activity.
- Confirm compensating controls restrict administrative access.
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-2021-1157 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.
