CVE-2024-21636

Home/CVE/view_component is a framework for building reusable, testable, and encapsulated view components in Ruby on Rails. Versio

CVE

view_component is a framework for building reusable, testable, and encapsulated view components in Ruby on Rails. Versio

view_component is a framework for building reusable, testable, and encapsulated view components in Ruby on Rails. Versions prior to 3.9.0 and 2.83.0 have a cross-site scripting vulnerability that has the potential to impact anyone rendering a component directly from a controller with the view_component gem. Note that only components that define a #call method (i.e. instead of using a sidecar template) are affected.

The return value of the #call method is not sanitized and can include user-defined content. In addition, the return value of the #output_postamble methodis not sanitized, which can also lead to cross-site scripting issues. Versions 3.9.0 and 2.83.0 have been released and fully mitigate both the #call and the #output_postamble vulnerabilities.

As a workaround, sanitize the return value of #call.

MEDIUM · CVSS 6.1 EPSS 0.00501

Schedule remediation

Public exploit or PoC is available

Sigma rules0 YARA rules0

Look this up elsewhere - one-click external pivots

NVD CVE.org CISA Vulners Exploit-DB GitHub PoC VulnCheck KEV GreyNoise

▸ How to read a CVE - triage first, then detect and patch

This page is every public fact about CVE-2024-21636, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.

Triage: should I act now? Four signals, and they are not interchangeable:

CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.

How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.

Then what - two workflows:

Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.

Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).

View attack path from CVE-2024-21636

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ATT&CK techniques

Techniques this CVE enables - linked via CWECAPECATT&CK. High◆ = named directly in ATT&CK or Nuclei templates.

T1190 · Exploit Public-Facing Application T1482 · Domain Trust Discovery

▤ Build a SIEM detection for these techniques

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CAPEC attack patterns

Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.

CAPEC-CAPEC-209 · XSS Using MIME Type Mismatch CAPEC-CAPEC-588 · DOM-Based XSS CAPEC-CAPEC-591 · Reflected XSS CAPEC-CAPEC-592 · Stored XSS CAPEC-CAPEC-63 · Cross-Site Scripting (XSS) CAPEC-CAPEC-85 · AJAX Footprinting

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Weakness Classification

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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Affected Products & Versions

viewcomponent view component< 2.83.0

viewcomponent view component>= 3.0.0 and < 3.9.0

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Affected Packages

Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.

RubyGems view_component MODERATE fixed in 3.9.0

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Public Exploits & PoCs

These PoC and exploit links come from public sources and are not verified to be safe or functional. Review the code before running anything, and treat unverified entries as untrusted.

pocPublic PoC (nvd-reference)

pocgithub.com · 1950github.com

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Scoring & Timeline

6.1

MEDIUM · CVSS v3.1 · [email protected]

View on NVD

Attack Vector

Network Adjacent Local Physical

Attack Complexity

Low High

Privileges Required

None Low High

User Interaction

None Required

Scope

Unchanged Changed

Confidentiality

None Low High

Integrity

None Low High

Availability

None Low High

Published to NVD04 Jan 2024 · 08:15 PM

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

SSVC triage · cisa-vulnrichment

Exploitation

none

Automatable

Technical impact

partial

SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.

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References & Sources

Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.

https://github.com/ViewComponent/view_component/commit/0d26944a8d2730ea40e60eae23d70684483e5017Patch

https://github.com/ViewComponent/view_component/commit/c43d8bafa7117cbce479669a423ab266de150697Patch

https://github.com/ViewComponent/view_component/pull/1962Issue Tracking

https://github.com/ViewComponent/view_component/security/advisories/GHSA-wf2x-8w6j-qw37Vendor Advisory