CRITICAL · 9.8

CVE-2016-4538

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_,...

Vulnerability Description

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.

CVSS Score

9.8

CRITICAL

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH

Affected Products

VendorProductVersions
PhpPhp<= 5.5.33
FedoraprojectFedora24
OpensuseLeap42.1

Related Weaknesses (CWE)

References

FAQ

What is CVE-2016-4538?

CVE-2016-4538 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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_,...

How severe is CVE-2016-4538?

CVE-2016-4538 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2016-4538?

Check the references section above for vendor advisories and patch information. Affected products include: Php Php, Fedoraproject Fedora, Opensuse Leap.