title: Null Pointer Dereference in PHP Session Upload Progress
description: In PHP versions 7.2.x below 7.2.28, 7.3.x below 7.3.15 and 7.4.x below 7.4.3, when using file upload functionality, if upload progress tracking is enabled, but session.upload_progress.cleanup is set to 0 (disabled), and the file upload fails, the upload procedure would try to clean up data that does not exist and encounter null pointer dereference, which would likely lead to a crash.
problem types: CWE-476 NULL Pointer Dereference
affected:
{
product: PHP
vendor: PHP Group
versions:
lessThan: 7.3.15, status: affected, version: 7.3.x, versionType: custom
lessThan: 7.4.3, status: affected, version: 7.4.x, versionType: custom
lessThan: 7.2.28, status: affected, version: 7.2.x, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.1
]
workarounds: Disable file uploading, file upload tracking or enable session.upload_progress.cleanup.