Vulnerability identifier: #VU45475

Vulnerability risk: Medium

CVSSv3.1: 4.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C]

CVE-ID: CVE-2010-4645

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
PHP
Universal components / Libraries / Scripting languages

Vendor: PHP Group

Description

The vulnerability allows a remote non-authenticated attacker to perform service disruption.

strtod.c, as used in the zend_strtod function in PHP 5.2 before 5.2.17 and 5.3 before 5.3.5, and other products, allows context-dependent attackers to cause a denial of service (infinite loop) via a certain floating-point value in scientific notation, which is not properly handled in x87 FPU registers, as demonstrated using 2.2250738585072011e-308.

Mitigation
Install update from vendor's website.

Vulnerable software versions

PHP: 5.2.0 - 5.2.16, 5.3.0 - 5.3.4

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External links
http://bugs.php.net/53632
http://hal.archives-ouvertes.fr/docs/00/28/14/29/PDF/floating-point-article.pdf
http://lists.apple.com/archives/Security-announce/2011//Oct/msg00003.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-January/053333.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-January/053355.html
http://marc.info/?l=bugtraq&m=133226187115472&w=2
http://marc.info/?l=bugtraq&m=133469208622507&w=2
http://secunia.com/advisories/42812
http://secunia.com/advisories/42843
http://secunia.com/advisories/43051
http://secunia.com/advisories/43189
http://slackware.com/security/viewer.php?l=slackware-security&y=2011&m=slackware-security.484686
http://support.apple.com/kb/HT5002
http://svn.php.net/viewvc/php/php-src/branches/PHP_5_2/Zend/zend_strtod.c?r1=266327&r2=307095&pathrev=307095
http://www.exploringbinary.com/php-hangs-on-numeric-value-2-2250738585072011e-308/
http://www.openwall.com/lists/oss-security/2011/01/05/2
http://www.openwall.com/lists/oss-security/2011/01/05/8
http://www.openwall.com/lists/oss-security/2011/01/06/5
http://www.redhat.com/support/errata/RHSA-2011-0195.html
http://www.redhat.com/support/errata/RHSA-2011-0196.html
http://www.securityfocus.com/bid/45668
http://www.ubuntu.com/usn/USN-1042-1
http://www.vupen.com/english/advisories/2011/0060
http://www.vupen.com/english/advisories/2011/0066
http://www.vupen.com/english/advisories/2011/0077
http://www.vupen.com/english/advisories/2011/0198
http://exchange.xforce.ibmcloud.com/vulnerabilities/64470

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.