Vulnerabilities > CVE-2011-2529 - Improper Restriction of Operations Within the Bounds of A Memory Buffer vulnerability in Digium Asterisk
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
NONE Availability impact
PARTIAL Summary
chan_sip.c in the SIP channel driver in Asterisk Open Source 1.6.x before 1.6.2.18.1 and 1.8.x before 1.8.4.3 does not properly handle '\0' characters in SIP packets, which allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via a crafted packet.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Buffer Overflow via Environment Variables This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
- Overflow Buffers Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
- Client-side Injection-induced Buffer Overflow This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
- Filter Failure through Buffer Overflow In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
- MIME Conversion An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.
Nessus
NASL family Denial of Service NASL id ASTERISK_AST_2011_010.NASL description According to the version in its SIP banner, the version of Asterisk running on the remote host is potentially affected by multiple denial of service vulnerabilities : - If a remote user sends a SIP packet with a NULL, Asterisk reads data past the NULL even though the buffer is actually truncated when copied, which could lead to an application crash. (AST-2011-008) - A remote user sending a SIP packet containing a Contact header with a missing left angle bracket causes Asterisk to access a NULL pointer, which could cause the application to crash. (AST-2011-009) - A memory address can be inadvertently transmitted over the network via IAX2 via an option control frame, which would cause the remote party to try to access it. (AST-2011-010) last seen 2020-06-01 modified 2020-06-02 plugin id 55457 published 2011-06-29 reporter This script is Copyright (C) 2011-2018 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/55457 title Asterisk Multiple Channel Drivers Denial of Service (AST-2011-008 / AST-2011-009 / AST-2011-010) NASL family Gentoo Local Security Checks NASL id GENTOO_GLSA-201110-21.NASL description The remote host is affected by the vulnerability described in GLSA-201110-21 (Asterisk: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in Asterisk. Please review the CVE identifiers referenced below for details. Impact : An unauthenticated remote attacker may execute code with the privileges of the Asterisk process or cause a Denial of Service. Workaround : There is no known workaround at this time. last seen 2020-06-01 modified 2020-06-02 plugin id 56625 published 2011-10-25 reporter This script is Copyright (C) 2011-2018 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/56625 title GLSA-201110-21 : Asterisk: Multiple vulnerabilities NASL family FreeBSD Local Security Checks NASL id FREEBSD_PKG_40544E8C9F7B11E09BEC6C626DD55A41.NASL description The Asterisk Development Team reports : AST-2011-008: If a remote user sends a SIP packet containing a NULL, Asterisk assumes available data extends past the null to the end of the packet when the buffer is actually truncated when copied. This causes SIP header parsing to modify data past the end of the buffer altering unrelated memory structures. This vulnerability does not affect TCP/TLS connections. AST-2011-009: A remote user sending a SIP packet containing a Contact header with a missing left angle bracket causes Asterisk to access a NULL pointer. AST-2011-010: A memory address was inadvertently transmitted over the network via IAX2 via an option control frame and the remote party would try to access it. Possible enumeration of SIP users due to differing authentication responses. last seen 2020-06-01 modified 2020-06-02 plugin id 55430 published 2011-06-27 reporter This script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/55430 title FreeBSD : Asterisk -- multiple vulnerabilities (40544e8c-9f7b-11e0-9bec-6c626dd55a41) NASL family Fedora Local Security Checks NASL id FEDORA_2011-8914.NASL description The Asterisk Development Team has announced the final maintenance release of Asterisk, version 1.6.2.19. This release is available for immediate download at http://downloads.asterisk.org/pub/telephony/asterisk/ Please note that Asterisk 1.6.2.19 is the final maintenance release from the 1.6.2 branch. Support for security related issues will continue until April 21, 2012. For more information about support of the various Asterisk branches, see https://wiki.asterisk.org/wiki/display/AST/Asterisk+Versions The release of Asterisk 1.6.2.19 resolves several issues reported by the community and would have not been possible without your participation. Thank you! The following is a sample of the issues resolved in this release : - Don last seen 2020-06-01 modified 2020-06-02 plugin id 55581 published 2011-07-13 reporter This script is Copyright (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/55581 title Fedora 14 : asterisk-1.6.2.19-1.fc14 (2011-8914) NASL family Debian Local Security Checks NASL id DEBIAN_DSA-2276.NASL description Paul Belanger reported a vulnerability in Asterisk identified as AST-2011-008(CVE-2011-2529 ) through which an unauthenticated attacker may crash an Asterisk server remotely. A package containing a NULL char causes the SIP header parser to alter unrelated memory structures. Jared Mauch reported a vulnerability in Asterisk identified as AST-2011-009through which an unauthenticated attacker may crash an Asterisk server remotely. If a user sends a package with a Contact header with a missing left angle bracket (<) the server will crash. A possible workaround is to disable chan_sip. The vulnerability identified as AST-2011-010(CVE-2011-2535 ) reported about an input validation error in the IAX2 channel driver. An unauthenticated attacker may crash an Asterisk server remotely by sending a crafted option control frame. last seen 2020-03-17 modified 2011-07-12 plugin id 55554 published 2011-07-12 reporter This script is Copyright (C) 2011-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/55554 title Debian DSA-2276-1 : asterisk - multiple denial of service
References
- http://downloads.asterisk.org/pub/security/AST-2011-008.diff
- http://downloads.asterisk.org/pub/security/AST-2011-008.html
- http://lists.fedoraproject.org/pipermail/package-announce/2011-July/062628.html
- http://secunia.com/advisories/45048
- http://secunia.com/advisories/45201
- http://secunia.com/advisories/45239
- http://securitytracker.com/id?1025706
- http://www.debian.org/security/2011/dsa-2276
- http://www.osvdb.org/73307
- http://www.securityfocus.com/bid/48431
- https://exchange.xforce.ibmcloud.com/vulnerabilities/68203