#VU110345 Insufficient Entropy in PHP - CVE-2008-2108

Vulnerability identifier: #VU110345

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2008-2108

CWE-ID: CWE-331

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
PHP
Universal components / Libraries / Scripting languages

Vendor: PHP Group

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

The GENERATE_SEED macro in PHP 4.x before 4.4.8 and 5.x before 5.2.5, when running on 64-bit systems, performs a multiplication that generates a portion of zero bits during conversion due to insufficient precision, which produces 24 bits of entropy and simplifies brute force attacks against protection mechanisms that use the rand and mt_rand functions.

Mitigation
Install update from vendor's website.

Vulnerable software versions

PHP: before

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External links
https://archives.neohapsis.com/archives/fulldisclosure/2008-05/0103.html
https://www.sektioneins.de/advisories/SE-2008-02.txt
https://www.mandriva.com/security/advisories?name=MDVSA-2008:130
https://www.redhat.com/support/errata/RHSA-2008-0582.html
https://www.mandriva.com/security/advisories?name=MDVSA-2008:128
https://www.mandriva.com/security/advisories?name=MDVSA-2008:125
https://secunia.com/advisories/31119
https://www.redhat.com/support/errata/RHSA-2008-0505.html
https://secunia.com/advisories/31200
https://www.redhat.com/archives/fedora-package-announce/2008-June/msg00773.html
https://secunia.com/advisories/30757
https://www.mandriva.com/security/advisories?name=MDVSA-2008:126
https://www.redhat.com/support/errata/RHSA-2008-0546.html
https://www.redhat.com/support/errata/RHSA-2008-0545.html
https://secunia.com/advisories/31124
https://www.mandriva.com/security/advisories?name=MDVSA-2008:127
https://www.redhat.com/support/errata/RHSA-2008-0544.html
https://www.mandriva.com/security/advisories?name=MDVSA-2008:129
https://www.ubuntu.com/usn/usn-628-1
https://secunia.com/advisories/30828
https://www.redhat.com/archives/fedora-package-announce/2008-June/msg00779.html
https://securityreason.com/securityalert/3859
https://secunia.com/advisories/35003
https://www.debian.org/security/2009/dsa-1789
https://secunia.com/advisories/32746
https://security.gentoo.org/glsa/glsa-200811-05.xml
https://exchange.xforce.ibmcloud.com/vulnerabilities/42226
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10844
https://www.securityfocus.com/archive/1/491683/100/0/threaded

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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.