Security readout for executives and security teams
Plain-English summary
CVE-2021-1271 is a stored cross-site scripting issue in the Cisco Web Security Appliance management interface. An already authenticated attacker with high privileges could save malicious input that later runs script in another interface user’s browser. The business risk is moderate because exploitation requires privileged access and user interaction, but it could still affect administrator sessions.
Executive priority
Treat this as a moderate-priority appliance management-plane issue. It is not described as actively exploited, but it affects administrator-facing systems and should be remediated during the next normal security maintenance cycle after confirming exposure.
Technical view
Cisco AsyncOS for Cisco WSA does not properly validate user-supplied input in a specific web management interface field. This can permit stored XSS, executing arbitrary script code in the affected interface context. CVSS v3.1 is 4.8 with network access, low attack complexity, high privileges required, user interaction required, changed scope, and low confidentiality/integrity impact.
Likely exposure
Exposure is limited to Cisco Web Security Appliance deployments running affected Cisco AsyncOS releases. The source bundle does not identify exact affected versions, so teams must confirm device inventory and version status against Cisco’s advisory.
Exploitation context
The provided sources do not report active exploitation, and the CVE is not listed as KEV. Exploitation requires an authenticated remote attacker with high privileges and a victim user interacting with the affected management interface.
Researcher notes
Key constraints are PR:H and UI:R, so practical impact depends on privileged account access and administrator interaction. The bundle lacks affected version details and fixed-release text; rely on Cisco’s advisory for exact product status and remediation instructions.
Mitigation direction
- Review Cisco’s advisory for affected and fixed AsyncOS release guidance.
- Inventory Cisco WSA devices and record current AsyncOS versions.
- Restrict management interface access to trusted administrative networks and users.
- Review administrative privileges and remove unnecessary management access.
Validation and detection
- Confirm whether Cisco WSA devices are present in the environment.
- Compare each AsyncOS version against Cisco’s advisory.
- Review who can authenticate to the WSA management interface.
- Check management activity logs for unexpected configuration or field changes.
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-2021-1271 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
- 20210120 Cisco Web Security Appliance Stored Cross-Site Scripting VulnerabilityCVE 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.