by Kastro
Paper/Archive/CVE-2021-21708

CVE-2021-21708

PHP Group PHP — UAF due to php_filter_float() failing

EPSS 3%CVSS 9.8
critical.is priorityof 100
47
CVSS 9.8 (NVD)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 87.4.874 × 2017.5No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

In PHP versions 7.4.x below 7.4.28, 8.0.x below 8.0.16, and 8.1.x below 8.1.3, when using filter functions with FILTER_VALIDATE_FLOAT filter and min/max limits, if the filter fails, there is a possibility to trigger use of allocated memory after free, which can result it crashes, and potentially in overwrite of other memory chunks and RCE. This issue affects: code that uses FILTER_VALIDATE_FLOAT with min/max limits.

Affected

ProductAffectedFixed inSource
PHP7.4.x – < 7.4.287.4.28CNA
PHP8.0.X – < 8.0.168.0.16CNA
PHP8.1.X – < 8.1.38.1.3CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
php (CNA)8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

References

refbugs.php.net/bug.php?id=81708refsecurity.netapp.com/advisory/ntap-20220325-0004advisorysecurity.gentoo.org/glsa/202209-20