Vulnerabilities > CVE-2017-14100 - OS Command Injection vulnerability in Digium Asterisk
Summary
In Asterisk 11.x before 11.25.2, 13.x before 13.17.1, and 14.x before 14.6.1 and Certified Asterisk 11.x before 11.6-cert17 and 13.x before 13.13-cert5, unauthorized command execution is possible. The app_minivm module has an "externnotify" program configuration option that is executed by the MinivmNotify dialplan application. The application uses the caller-id name and number as part of a built string passed to the OS shell for interpretation and execution. Since the caller-id name and number can come from an untrusted source, a crafted caller-id name or number allows an arbitrary shell command injection.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Command Line Execution through SQL Injection An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.
- Command Delimiters An attack of this type exploits a programs' vulnerabilities that allows an attacker's commands to be concatenated onto a legitimate command with the intent of targeting other resources such as the file system or database. The system that uses a filter or a blacklist input validation, as opposed to whitelist validation is vulnerable to an attacker who predicts delimiters (or combinations of delimiters) not present in the filter or blacklist. As with other injection attacks, the attacker uses the command delimiter payload as an entry point to tunnel through the application and activate additional attacks through SQL queries, shell commands, network scanning, and so on.
- Exploiting Multiple Input Interpretation Layers An attacker supplies the target software with input data that contains sequences of special characters designed to bypass input validation logic. This exploit relies on the target making multiples passes over the input data and processing a "layer" of special characters with each pass. In this manner, the attacker can disguise input that would otherwise be rejected as invalid by concealing it with layers of special/escape characters that are stripped off by subsequent processing steps. The goal is to first discover cases where the input validation layer executes before one or more parsing layers. That is, user input may go through the following logic in an application: In such cases, the attacker will need to provide input that will pass through the input validator, but after passing through parser2, will be converted into something that the input validator was supposed to stop.
- Argument Injection An attacker changes the behavior or state of a targeted application through injecting data or command syntax through the targets use of non-validated and non-filtered arguments of exposed services or methods.
- OS Command Injection In this type of an attack, an adversary injects operating system commands into existing application functions. An application that uses untrusted input to build command strings is vulnerable. An adversary can leverage OS command injection in an application to elevate privileges, execute arbitrary commands and compromise the underlying operating system.
Nessus
NASL family Debian Local Security Checks NASL id DEBIAN_DSA-3964.NASL description Multiple vulnerabilities have been discovered in Asterisk, an open source PBX and telephony toolkit, which may result in disclosure of RTP connections or the execution of arbitrary shell commands. For additional information please refer to the upstream advisories: http://downloads.asterisk.org/pub/security/AST-2017-005.html, http://downloads.asterisk.org/pub/security/AST-2017-006.html last seen 2020-06-01 modified 2020-06-02 plugin id 102931 published 2017-09-05 reporter This script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/102931 title Debian DSA-3964-1 : asterisk - security update code # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Debian Security Advisory DSA-3964. The text # itself is copyright (C) Software in the Public Interest, Inc. # include("compat.inc"); if (description) { script_id(102931); script_version("3.7"); script_cvs_date("Date: 2018/11/10 11:49:38"); script_cve_id("CVE-2017-14099", "CVE-2017-14100"); script_xref(name:"DSA", value:"3964"); script_name(english:"Debian DSA-3964-1 : asterisk - security update"); script_summary(english:"Checks dpkg output for the updated package"); script_set_attribute( attribute:"synopsis", value:"The remote Debian host is missing a security-related update." ); script_set_attribute( attribute:"description", value: "Multiple vulnerabilities have been discovered in Asterisk, an open source PBX and telephony toolkit, which may result in disclosure of RTP connections or the execution of arbitrary shell commands. For additional information please refer to the upstream advisories: http://downloads.asterisk.org/pub/security/AST-2017-005.html, http://downloads.asterisk.org/pub/security/AST-2017-006.html" ); script_set_attribute( attribute:"see_also", value:"http://downloads.asterisk.org/pub/security/AST-2017-005.html" ); script_set_attribute( attribute:"see_also", value:"http://downloads.asterisk.org/pub/security/AST-2017-006.html" ); script_set_attribute( attribute:"see_also", value:"https://packages.debian.org/source/jessie/asterisk" ); script_set_attribute( attribute:"see_also", value:"https://packages.debian.org/source/stretch/asterisk" ); script_set_attribute( attribute:"see_also", value:"https://www.debian.org/security/2017/dsa-3964" ); script_set_attribute( attribute:"solution", value: "Upgrade the asterisk packages. For the oldstable distribution (jessie), these problems have been fixed in version 1:11.13.1~dfsg-2+deb8u3. For the stable distribution (stretch), these problems have been fixed in version 1:13.14.1~dfsg-2+deb9u1." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk"); script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0"); script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0"); script_set_attribute(attribute:"patch_publication_date", value:"2017/09/04"); script_set_attribute(attribute:"plugin_publication_date", value:"2017/09/05"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof."); script_family(english:"Debian Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l"); exit(0); } include("audit.inc"); include("debian_package.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian"); if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING); flag = 0; if (deb_check(release:"8.0", prefix:"asterisk", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-config", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-dahdi", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-dbg", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-dev", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-doc", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-mobile", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-modules", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-mp3", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-mysql", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-ooh323", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-voicemail", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-voicemail-imapstorage", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-voicemail-odbcstorage", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"8.0", prefix:"asterisk-vpb", reference:"1:11.13.1~dfsg-2+deb8u3")) flag++; if (deb_check(release:"9.0", prefix:"asterisk", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-config", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-dahdi", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-dev", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-doc", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-mobile", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-modules", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-mp3", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-mysql", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-ooh323", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-voicemail", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-voicemail-imapstorage", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-voicemail-odbcstorage", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (deb_check(release:"9.0", prefix:"asterisk-vpb", reference:"1:13.14.1~dfsg-2+deb9u1")) flag++; if (flag) { if (report_verbosity > 0) security_hole(port:0, extra:deb_report_get()); else security_hole(0); exit(0); } else audit(AUDIT_HOST_NOT, "affected");
NASL family Debian Local Security Checks NASL id DEBIAN_DLA-1122.NASL description A security vulnerability was discovered in Asterisk, an Open Source PBX and telephony toolkit, that may lead to unauthorized command execution. The app_minivm module has an last seen 2020-03-17 modified 2017-10-06 plugin id 103683 published 2017-10-06 reporter This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/103683 title Debian DLA-1122-1 : asterisk security update code #%NASL_MIN_LEVEL 80502 # # (C) Tenable Network Security, Inc. # # The descriptive text and package checks in this plugin were # extracted from Debian Security Advisory DLA-1122-1. The text # itself is copyright (C) Software in the Public Interest, Inc. # include("compat.inc"); if (description) { script_id(103683); script_version("2.7"); script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/12"); script_cve_id("CVE-2017-14100"); script_name(english:"Debian DLA-1122-1 : asterisk security update"); script_summary(english:"Checks dpkg output for the updated packages."); script_set_attribute( attribute:"synopsis", value:"The remote Debian host is missing a security update." ); script_set_attribute( attribute:"description", value: "A security vulnerability was discovered in Asterisk, an Open Source PBX and telephony toolkit, that may lead to unauthorized command execution. The app_minivm module has an 'externnotify' program configuration option that is executed by the MinivmNotify dialplan application. The application uses the caller-id name and number as part of a built string passed to the OS shell for interpretation and execution. Since the caller-id name and number can come from an untrusted source, a crafted caller-id name or number allows an arbitrary shell command injection. For Debian 7 'Wheezy', these problems have been fixed in version 1:1.8.13.1~dfsg1-3+deb7u7. We recommend that you upgrade your asterisk packages. NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues." ); script_set_attribute( attribute:"see_also", value:"https://lists.debian.org/debian-lts-announce/2017/10/msg00002.html" ); script_set_attribute( attribute:"see_also", value:"https://packages.debian.org/source/wheezy/asterisk" ); script_set_attribute(attribute:"solution", value:"Upgrade the affected packages."); script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P"); script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C"); script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"); script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C"); script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available"); script_set_attribute(attribute:"exploit_available", value:"false"); script_set_attribute(attribute:"plugin_type", value:"local"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-config"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-dahdi"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-dbg"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-dev"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-doc"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-mobile"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-modules"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-mp3"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-mysql"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-ooh323"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-voicemail"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-voicemail-imapstorage"); script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:asterisk-voicemail-odbcstorage"); script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:7.0"); script_set_attribute(attribute:"patch_publication_date", value:"2017/10/05"); script_set_attribute(attribute:"plugin_publication_date", value:"2017/10/06"); script_end_attributes(); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2017-2020 and is owned by Tenable, Inc. or an Affiliate thereof."); script_family(english:"Debian Local Security Checks"); script_dependencies("ssh_get_info.nasl"); script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l"); exit(0); } include("audit.inc"); include("debian_package.inc"); if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED); if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian"); if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING); flag = 0; if (deb_check(release:"7.0", prefix:"asterisk", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-config", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-dahdi", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-dbg", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-dev", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-doc", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-mobile", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-modules", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-mp3", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-mysql", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-ooh323", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-voicemail", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-voicemail-imapstorage", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (deb_check(release:"7.0", prefix:"asterisk-voicemail-odbcstorage", reference:"1:1.8.13.1~dfsg1-3+deb7u7")) flag++; if (flag) { if (report_verbosity > 0) security_hole(port:0, extra:deb_report_get()); else security_hole(0); exit(0); } else audit(AUDIT_HOST_NOT, "affected");
NASL family Gentoo Local Security Checks NASL id GENTOO_GLSA-201710-29.NASL description The remote host is affected by the vulnerability described in GLSA-201710-29 (Asterisk: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in Asterisk. Please review the referenced CVE identifiers for details. Impact : A remote attacker could execute arbitrary code, cause a denial of service condition, or cause an unauthorized data disclosure by enticing a user to run malicious code. Workaround : There is no known workaround at this time. last seen 2020-06-01 modified 2020-06-02 plugin id 104230 published 2017-10-30 reporter This script is Copyright (C) 2017-2018 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/104230 title GLSA-201710-29 : Asterisk: Multiple vulnerabilities NASL family Misc. NASL id ASTERISK_AST_2017_005-007.NASL description According to its SIP banner, the version of Asterisk running on the remote host is 11.x prior to 11.25.2, 13.x prior to 13.17.1, 14.x prior to 14.6.1, 11.6 prior to 11.6-cert17, or 13.13 prior to 13.13-cert5. It is therefore, affected by multiple vulnerabilities as described in AST-2017-005, AST-2017-006, and AST-2017-007. Note for AST-2017-005, only 11.4.0 is affected in the 11.x branch. Also note that Nessus has not tested for these issues but has instead relied only on the application last seen 2020-06-01 modified 2020-06-02 plugin id 102958 published 2017-09-05 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/102958 title Asterisk 11.x < 11.25.2 / 11.6 < 11.6-cert17 / 13.x < 13.17.1 / 14.x < 14.6.1 / 13.13 < 13.13-cert5 Multiple Vulnerabilities (AST-2017-005 - AST-2017-007) NASL family FreeBSD Local Security Checks NASL id FREEBSD_PKG_C599F95C8EE511E78BE8001999F8D30B.NASL description The Asterisk project reports : AST-2017-005 - A change was made to the strict RTP support in the RTP stack to better tolerate late media when a reinvite occurs. When combined with the symmetric RTP support this introduced an avenue where media could be hijacked. Instead of only learning a new address when expected the new code allowed a new source address to be learned at all times. AST-2017-006 - The app_minivm module has an last seen 2020-06-01 modified 2020-06-02 plugin id 102940 published 2017-09-05 reporter This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/102940 title FreeBSD : asterisk -- Unauthorized data disclosure and shell access command injection in app_minivm (c599f95c-8ee5-11e7-8be8-001999f8d30b)
References
- http://downloads.asterisk.org/pub/security/AST-2017-006.html
- http://downloads.asterisk.org/pub/security/AST-2017-006.html
- http://www.debian.org/security/2017/dsa-3964
- http://www.debian.org/security/2017/dsa-3964
- http://www.securitytracker.com/id/1039252
- http://www.securitytracker.com/id/1039252
- https://bugs.debian.org/873908
- https://bugs.debian.org/873908
- https://issues.asterisk.org/jira/browse/ASTERISK-27103
- https://issues.asterisk.org/jira/browse/ASTERISK-27103
- https://security.gentoo.org/glsa/201710-29
- https://security.gentoo.org/glsa/201710-29