Cyber Resilience

CVE-2021-1271

Medium

Published: 20 January 2021

Published
20 January 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 4.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0017 38.0th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-1271 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Cisco Web Security Virtual Appliance. Its CVSS base score is 4.8 (Medium).

Operationally, ranked at the 38.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A vulnerability in the web-based management interface of Cisco AsyncOS for Cisco Web Security Appliance (WSA) could allow an authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against a user of the interface of an affected device.…

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The vulnerability exists because the web-based management interface does not properly validate user-supplied input. An attacker could exploit this vulnerability by inserting malicious data into a specific data field in an affected interface. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

cisco
web security virtual appliance
≤ 12.5.1

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References