Cyber Resilience

CVE-2021-22886

Medium

Published: 26 March 2021

Published
26 March 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0075 73.6th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-22886 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Rocket.Chat Rocket.Chat. Its CVSS base score is 6.1 (Medium).

Operationally, ranked in the top 26.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Rocket.Chat before 3.11, 3.10.5, 3.9.7, 3.8.8 is vulnerable to persistent cross-site scripting (XSS) using nested markdown tags allowing a remote attacker to inject arbitrary JavaScript in a message. This flaw leads to arbitrary file read and RCE on Rocket.Chat desktop…

more

app.

CWE(s)

Related Threats

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

Affected Assets

rocket.chat
rocket.chat
3.11.0 · ≤ 3.8.8 · 3.9.0 — 3.9.7 · 3.10.0 — 3.10.5

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