Buffer overflow in PHP
CVE-2017-8923
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.072 (94.1th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 94.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.072 · newest: 0.072 · change: 0.000
Affected products
Weakness classification (CWE)
References
- www.securityfocus.com/bid/98518 (VDB Entry, Third Party Advisory, vdb-entry)
- bugs.php.net/bug.php (Exploit, Issue Tracking, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2017-8923?
- CVE-2017-8923 is a critical-severity vulnerability in PHP, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2017-05-12.
- How severe is CVE-2017-8923?
- Critical severity. CVSS v3 base score is 9.8 out of 10.