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vulnerability CVE-2014-0198

OpenSSL: NULL pointer dereference via SSL_MODE_RELEASE_BUFFERS

Synthesis of the vulnerability

An attacker can dereference a NULL pointer in OpenSSL applications using SSL_MODE_RELEASE_BUFFERS, in order to trigger a denial of service.
Vulnerable systems: ArubaOS, ProxyAV, ProxySG par Blue Coat, SGOS by Blue Coat, Cisco ASR, Cisco ATA, Cisco ACE, ASA, AsyncOS, Cisco Catalyst, CiscoWorks, Cisco Content SMA, Cisco CSS, Cisco ESA, IOS by Cisco, IOS XE Cisco, IOS XR Cisco, Cisco IPS, IronPort Email, IronPort Management, IronPort Web, Nexus by Cisco, NX-OS, Prime Collaboration Assurance, Prime Collaboration Manager, Prime Infrastructure, Cisco PRSM, Cisco Router, Secure ACS, Cisco CUCM, Cisco Manager Attendant Console, Cisco Unified CCX, Cisco IP Phone, Cisco MeetingPlace, Cisco Wireless IP Phone, Cisco Unity ~ precise, WebNS, Cisco WSA, Debian, Avamar, EMC CAVA, EMC CEE, EMC CEPA, Celerra FAST, Celerra NS, Celerra NX4, EMC CMDCE, Connectrix Switch, ECC, NetWorker, PowerPath, Unisphere EMC, VNX Operating Environment, VNX Series, BIG-IP Hardware, TMOS, Fedora, FreeBSD, ProCurve Switch, HP Switch, AIX, Juniper J-Series, Junos OS, Junos Pulse, Juniper Network Connect, Juniper UAC, McAfee Web Gateway, NetBSD, OpenBSD, OpenSSL, openSUSE, Solaris, Polycom CMA, HDX, RealPresence Collaboration Server, Polycom VBP, RHEL, ACE Agent, ACE Server, RSA Authentication Agent, RSA Authentication Manager, SecurID, ROS, ROX, RuggedSwitch, SIMATIC, Slackware, stunnel, Ubuntu, ESXi, vCenter Server, VMware vSphere, VMware vSphere Hypervisor.
Severity of this threat: 3/4.
Consequences of a hack: denial of service on server, denial of service on service.
Pirate's origin: internet client.
Creation date: 02/05/2014.
Revisions dates: 02/05/2014, 05/06/2014.
Références of this weakness: 3321, aid-06062014, c04347622, CERTFR-2014-AVI-253, CERTFR-2014-AVI-254, CERTFR-2014-AVI-255, CERTFR-2014-AVI-260, CERTFR-2014-AVI-274, CERTFR-2014-AVI-279, CERTFR-2014-AVI-286, cisco-sa-20140605-openssl, CTX140876, CVE-2014-0198, DOC-53313, DSA-2931-1, FEDORA-2014-17576, FEDORA-2014-17587, FEDORA-2014-7101, FEDORA-2014-7102, FreeBSD-SA-14:10.openssl, HPSBHF03052, JSA10629, MDVSA-2014:080, MDVSA-2015:062, NetBSD-SA2014-006, openSUSE-SU-2014:0634-1, openSUSE-SU-2014:0635-1, RHSA-2014:0625-01, RHSA-2014:0628-01, RHSA-2014:0679-01, SA40006, SA80, SB10075, SOL15329, SSA:2014-156-03, SSA-234763, USN-2192-1, VIGILANCE-VUL-14690, VMSA-2014-0006, VMSA-2014-0006.1, VMSA-2014-0006.10, VMSA-2014-0006.11, VMSA-2014-0006.2, VMSA-2014-0006.3, VMSA-2014-0006.4, VMSA-2014-0006.5, VMSA-2014-0006.6, VMSA-2014-0006.7, VMSA-2014-0006.8, VMSA-2014-0006.9.

Description of the vulnerability

The SSL_set_mode() function of OpenSSL defines the behavior of the library. The SSL_MODE_RELEASE_BUFFERS parameter, added in version 1.0.0, indicates to free the memory as soon as it it not needed anymore. The SSL module of Apache httpd uses it when Apache is configured to save memory.

The do_ssl3_write() function of the ssl/s3_pkt.c file sends SSLv3 packets. After sending data, the memory can be freed if SSL_MODE_RELEASE_BUFFERS is used, so a pointer can be NULL. However, OpenSSL does not check if this pointer is NULL, before using it.

An attacker can therefore dereference a NULL pointer in OpenSSL applications using SSL_MODE_RELEASE_BUFFERS, in order to trigger a denial of service.
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