CVE-2021-23435
The vulnerability can be possible when users are able to set the value of session[:return_to].
Does this matter?
Lower severity and a low EPSS score (0.70%). Track it; it rarely justifies an emergency change on its own.
Description
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 the external domain that comes after the slashes (http://example.com).
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 0.70% probability · 53th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-601
- Affected
- thoughtbot/clearance
- Source
- report@snyk.io
EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/thoughtbot/clearance/pull/945Patch, Third Party Advisory
- https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284Third Party Advisory
- https://github.com/thoughtbot/clearance/pull/945Patch, Third Party Advisory
- https://snyk.io/vuln/SNYK-RUBY-CLEARANCE-1577284Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.