CVE-2017-8923 Information

Description

The zend_string_extend function in Zend/zend_string.h in PHP through 7.1.5 does not prevent changes to string objects that result in a negative length which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact by leveraging a script’s use of .= with a long string.

CVSS Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Reference

http://www.securityfocus.com/bid/98518 https://bugs.php.net/bug.php?id=74577

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

9.8