Cyber Resilience

CVE-2021-23435

High

Published: 12 September 2021

Published
12 September 2021
Modified
21 November 2024
KEV Added
—
Patch
—
CVSS Score v3.1 7.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
EPSS Score 0.0028 51.9th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-23435 is a high-severity Open Redirect (CWE-601) vulnerability in Thoughtbot Clearance. Its CVSS base score is 7.6 (High).

Operationally, ranked in the top 48.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

This affects the package clearance before 2.5.0. The vulnerability can be possible when users are able to set the value of session[:return_to]. If the value used for return_to contains multiple leading slashes (/////example.com) the user ends up being redirected to…

more

the external domain that comes after the slashes (http://example.com).

CWE(s)
CWE-601

Related Threats

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

Affected Assets

thoughtbot
clearance
≤ 2.5.0

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.

AT-2 Literacy Training and Awareness
addresses: CWE-601

Security awareness includes verifying URLs and avoiding untrusted redirects that lead to malicious sites.

SI-10 Information Input Validation
addresses: CWE-601

Validates redirect targets and URLs to ensure they conform to allowed destinations.

References