Cyber Resilience

CVE-2022-39197

XSS in Helpsystems Cobalt Strike ≤ 4.7.1

CISA KEVActive ExploitationEUVD ExploitedXSS
Published
22 September 2022
Modified
03 November 2025
KEV Added
30 March 2023
Patch / advisory
CVSS Score v3.1 6.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.46 99th percentile
Risk Priority 75 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-2022-39197 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Helpsystems Cobalt Strike. Its CVSS base score is 6.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked in the top 1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

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

An XSS vulnerability exists in HelpSystems Cobalt Strike through version 4.7. The flaw resides in the teamserver component and permits a remote attacker to execute arbitrary HTML by supplying a malformed username field inside a Cobalt Strike payload.

Exploitation requires an attacker to first inspect a generated payload, extract its configuration, and then either alter the username field in that payload or craft a new payload containing the same information with a deliberately malformed username. Successful exploitation results in HTML execution on the teamserver with a CVSS score of 6.1 under CWE-79.

Cobalt Strike released an out-of-band update to version 4.7.1 to address the issue. The vulnerability appears in the CISA Known Exploited Vulnerabilities catalog, confirming observed real-world exploitation activity. The associated EPSS score has remained near 0.20 without a pronounced increase after disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

An XSS (Cross Site Scripting) vulnerability was found in HelpSystems Cobalt Strike through 4.7 that allowed a remote attacker to execute HTML on the Cobalt Strike teamserver. To exploit the vulnerability, one must first inspect a Cobalt Strike payload, and…

more

then modify the username field in the payload (or create a new payload with the extracted information and then modify that username field to be malformed).

CWE(s)
KEV Date Added
30 March 2023

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.
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.
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
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.
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.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2021-26829Shared CWE-79both on KEV
CVE-2014-2120Shared CWE-79both on KEV
CVE-2019-18426Shared CWE-79both on KEV
CVE-2023-5631Shared CWE-79both on KEV
CVE-2018-6882Shared CWE-79both on KEV
CVE-2020-35730Shared CWE-79both on KEV
CVE-2020-11023Shared CWE-79both on KEV
CVE-2023-37580Shared CWE-79both on KEV
CVE-2022-27926Shared CWE-79both on KEV
CVE-2020-3580Shared CWE-79both on KEV

Affected Assets

helpsystems
cobalt strike
≤ 4.7.1

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

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.

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 target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).

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.

finds

Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.

prevents

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

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.

prevents

Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.

prevents

Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.

References