CVE-2016-4538

Public Exploit

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.

Category

9.8
CVSS
Severity: Critical
CVSS 3.0 •
CVSS 2.0 •
EPSS 2.47% Top 20%
Vendor Advisory opensuse.org Vendor Advisory gentoo.org Vendor Advisory redhat.com Vendor Advisory debian.org Vendor Advisory opensuse.org Vendor Advisory fedoraproject.org
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05320149
http://lists.opensuse.org/opensuse-updates/2016-06/msg00027.html vendor advisory
https://security.gentoo.org/glsa/201611-22 vendor advisory
https://bugs.php.net/bug.php?id=72093 exploit
http://www.securityfocus.com/bid/90173 vdb entry
http://rhn.redhat.com/errata/RHSA-2016-2750.html vendor advisory
http://www.openwall.com/lists/oss-security/2016/05/05/21 mailing list
http://www.debian.org/security/2016/dsa-3602 vendor advisory
https://git.php.net/?p=php-src.git%3Ba=commit%3Bh=d650063a0457aec56364e4005a636dc6c401f9cd
http://php.net/ChangeLog-5.php patch
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05390722
http://php.net/ChangeLog-7.php patch
https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
http://lists.opensuse.org/opensuse-updates/2016-05/msg00086.html vendor advisory
http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183736.html vendor advisory

Frequently Asked Questions

What is the severity of CVE-2016-4538?
CVE-2016-4538 has been scored as a critical severity vulnerability.
How to fix CVE-2016-4538?
To fix CVE-2016-4538, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2016-4538 being actively exploited in the wild?
It is possible that CVE-2016-4538 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~2% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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