CVE-2021-21705
Incorrect URL validation in FILTER_VALIDATE_URL
5.3
MEDIUM
CVSS 3.1
EPSS 0.29%
Description
In PHP versions 7.3.x below 7.3.29, 7.4.x below 7.4.21 and 8.0.x below 8.0.8, when using URL validation functionality via filter_var() function with FILTER_VALIDATE_URL parameter, an URL with invalid password field can be accepted as valid. This can lead to the code incorrectly parsing the URL and potentially leading to other security implications - like contacting a wrong server or making a wrong access decision.
How to fix CVE-2021-21705
To remediate CVE-2021-21705, upgrade the affected package to a fixed version below.
- —upgrade to 7.3.29 or later
- —upgrade to 7.3.29 or later
- —upgrade to 7.3.29 or later
- —upgrade to 7.4.21-1+deb11u1 or later
Is CVE-2021-21705 being exploited?
Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- >= 7.3.0, < 7.3.29, >= 7.4.0, < 7.4.21, >= 8.0.0, < 8.0.8
- >= 7.3.0, < 7.3.29, >= 7.4.0, < 7.4.21, >= 8.0.0, < 8.0.8
- >= 7.3.0, < 7.3.29, >= 7.4.0, < 7.4.21, >= 8.0.0, < 8.0.8
- from 0, < 7.4.21-1+deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |