CVE-2021-21708

Published: 31 December 2021

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.

Notes

Author	Note
sbeattie	PEAR issues should go against php-pear as of xenial
rodrigo-zaiden	the issue was introduced in PHP 7.4, seems like it was in commit https://github.com/php/php-src/commit/07df6594

Priority

Cvss 3 Severity Score

9.8

Score breakdown

Status

Package	Release	Status
php5 Launchpad, Ubuntu, Debian	bionic	Does not exist
	focal	Does not exist
	impish	Does not exist
	jammy	Does not exist
	trusty	Not vulnerable (code not present)
	upstream	Not vulnerable (code not present)
	xenial	Does not exist
php7.0 Launchpad, Ubuntu, Debian	bionic	Does not exist
	focal	Does not exist
	impish	Does not exist
	jammy	Does not exist
	trusty	Does not exist
	upstream	Not vulnerable (code not present)
	xenial	Not vulnerable (code not present)
php7.2 Launchpad, Ubuntu, Debian	bionic	Not vulnerable (code not present)
	focal	Does not exist
	impish	Does not exist
	jammy	Does not exist
	trusty	Does not exist
	upstream	Not vulnerable (code not present)
	xenial	Does not exist
php7.4 Launchpad, Ubuntu, Debian	bionic	Does not exist
	focal	Released (7.4.3-4ubuntu2.9)
	impish	Does not exist
	jammy	Does not exist
	trusty	Does not exist
	upstream	Released (7.4.28)
	xenial	Does not exist
	Patches: upstream: https://github.com/php/php-src/commit/dce5e561a63fc970de722636ad8c09e9b079e8ae
php8.0 Launchpad, Ubuntu, Debian	bionic	Does not exist
	focal	Does not exist
	impish	Released (8.0.8-1ubuntu0.2)
	jammy	Does not exist
	trusty	Does not exist
	upstream	Needs triage
	xenial	Does not exist
php8.1 Launchpad, Ubuntu, Debian	bionic	Does not exist
	focal	Does not exist
	impish	Does not exist
	jammy	Released (8.1.2-1ubuntu1)
	trusty	Does not exist
	upstream	Released (8.1.3)
	xenial	Does not exist
	Patches: upstream: https://github.com/php/php-src/commit/82f1bf1b6bc3a43aba62214870e6d0931e93a6d9

Severity score breakdown

Parameter	Value
Base score	9.8
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Bugs

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