CVE-2016-4538
CRITICAL severity · CVSS 9.8 · Improper input validation
9.8CVSS CRITICAL
Summary
The bcpowmod function in ext/bcmath/bcmath.c in PHP before 5.5.35, 5.6.x before 5.6.21, and 7.x before 7.0.6 modifies certain data structures without considering whether they are copies of the _zero_, _one_, or _two_ global variable, which allows remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted call.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)6%
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: http://php.net/ChangeLog-5.php ↗
Additional information
- NVD record
- http://php.net/ChangeLog-5.phpPatch
- http://php.net/ChangeLog-7.phpPatch
- http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183736.html
- http://lists.opensuse.org/opensuse-updates/2016-05/msg00086.html
- http://lists.opensuse.org/opensuse-updates/2016-06/msg00027.html
- http://rhn.redhat.com/errata/RHSA-2016-2750.html
- http://www.debian.org/security/2016/dsa-3602
- http://www.openwall.com/lists/oss-security/2016/05/05/21