Cyber Resilience

CVE-2022-21145

XSS in Lansweeper 9.1.20.2

Public PoCHigh EPSSXSS
Published
14 April 2022
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 4.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.78 99.5th percentile
Risk Priority 70 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2022-21145 is a medium-severity Basic XSS (CWE-80) vulnerability in Lansweeper Lansweeper. Its CVSS base score is 4.8 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked in the top 0.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A stored cross-site scripting vulnerability exists in the WebUserActions.aspx functionality of Lansweeper 9.1.20.2. Tracked as CVE-2022-21145 with associated CWEs 79 and 80, the flaw allows arbitrary JavaScript code injection when a specially crafted HTTP request is processed by the affected component.

An attacker with high privileges can exploit the issue over the network by sending the malicious request, leading to JavaScript execution that affects other users who interact with the page. The CVSS 4.8 score reflects the combination of network attack vector, low attack complexity, high privileges required, user interaction needed, and limited confidentiality and integrity consequences with no availability impact.

References from Talos Intelligence and the Lansweeper changelog provide further details on the issue. The associated EPSS score rose from a low baseline to a peak of 0.0661 on 2025-12-11 before receding to the current value of 0.0411.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

A stored cross-site scripting vulnerability exists in the WebUserActions.aspx functionality of Lansweeper lansweeper 9.1.20.2. A specially-crafted HTTP request can lead to arbitrary Javascript code injection. An attacker can send an HTTP request to trigger this vulnerability.

CWE(s)
CWE-80CWE-79

Related Threats

MITRE ATT&CK Enterprise Techniques

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
attack.mitre.org →
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
attack.mitre.org →
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-30615Shared CWE-79, CWE-80
CVE-2023-28851Shared CWE-79, CWE-80
CVE-2023-41048Shared CWE-79, CWE-80
CVE-2022-36096Shared CWE-79, CWE-80
CVE-2023-25833Shared CWE-79, CWE-80
CVE-2023-23548Shared CWE-79, CWE-80
CVE-2023-26046Shared CWE-79, CWE-80
CVE-2023-29110Shared CWE-79, CWE-80
CVE-2023-35153Shared CWE-79, CWE-80
CVE-2023-20228Shared CWE-79, CWE-80

Affected Assets

lansweeper
lansweeper
9.1.20.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.3.2
  • V1.2.1
  • V1.3.1

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.

CA-8 Penetration Testing
addresses: CWE-79

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

SI-10 Information Input Validation
addresses: CWE-79

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

SI-15 Information Output Filtering
addresses: CWE-79

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

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require output encoding and input validation that prevent basic XSS.

PR.PS-02 partial match
prevents

Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches unneutralized script tags before release.

A.5.6 Contact with special interest groups partial match
prevents

Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.

A.5.7 Threat intelligence partial match
prevents

Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and output encoding that directly prevent basic XSS.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for neutralization of script-related HTML tags.

A.8.28 Secure coding partial match
prevents

Secure coding standards require proper escaping of <, >, & to block XSS.

References