CVE-2017-8923

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 Metrics

• v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• v2.0•HIGH•Score: 7.5AV:N/AC:L/Au:N/C:P/I:P/A:P

EPSS Trends

Current EPSS score: 4.59%• Percentile: 89%

Techniques & Countermeasures

• CWE-787•Out-of-bounds Write

  The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

• Unknown•PHP

  < 7.4.24 | ≥ 8.0.0, < 8.0.11

References (3)

• http://www.securityfocus.com/bid/98518
• https://bugs.php.net/bug.php?id=74577
• https://security.netapp.com/advisory/ntap-20241227-0007/