Vulnerabilities > CVE-2018-7284 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Digium Asterisk

047910
CVSS 5.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
PARTIAL
network
low complexity
digium
debian
CWE-119
nessus
exploit available
NVD
Published: 2018-02-22
Updated: 2019-03-01

Summary

A Buffer Overflow issue was discovered in Asterisk through 13.19.1, 14.x through 14.7.5, and 15.x through 15.2.1, and Certified Asterisk through 13.18-cert2. When processing a SUBSCRIBE request, the res_pjsip_pubsub module stores the accepted formats present in the Accept headers of the request. This code did not limit the number of headers it processed, despite having a fixed limit of 32. If more than 32 Accept headers were present, the code would write outside of its memory and cause a crash.

Vulnerable Configurations

Part Description Count
Application
Digium
1184
OS
Debian
1

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.

Exploit-Db

descriptionAsterisk chan_pjsip 15.2.0 - 'SUBSCRIBE' Stack Corruption. CVE-2018-7284. Dos exploit for Linux platform. Tags: Denial of Service (DoS)
fileexploits/linux/dos/44184.py
idEDB-ID:44184
last seen2018-02-27
modified2018-02-27
platformlinux
port5060
published2018-02-27
reporterExploit-DB
sourcehttps://www.exploit-db.com/download/44184/
titleAsterisk chan_pjsip 15.2.0 - 'SUBSCRIBE' Stack Corruption
typedos

Nessus

  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-4320.NASL
    descriptionMultiple vulnerabilities have been discovered in Asterisk, an open source PBX and telephony toolkit, which may result in denial of service or information disclosure.
    last seen2020-06-01
    modified2020-06-02
    plugin id118158
    published2018-10-17
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/118158
    titleDebian DSA-4320-1 : 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-4320. The text 
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(118158);
  script_version("1.4");
  script_cvs_date("Date: 2019/04/05 23:25:05");

  script_cve_id("CVE-2018-12227", "CVE-2018-17281", "CVE-2018-7284", "CVE-2018-7286");
  script_xref(name:"DSA", value:"4320");

  script_name(english:"Debian DSA-4320-1 : 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 denial of
service or information disclosure."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=891227"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=891228"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=902954"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=909554"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://security-tracker.debian.org/tracker/source-package/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/2018/dsa-4320"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Upgrade the asterisk packages.

For the stable distribution (stretch), these problems have been fixed
in version 1:13.14.1~dfsg-2+deb9u4."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  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:9.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/10/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/10/17");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018-2019 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:"9.0", prefix:"asterisk", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-config", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-dahdi", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-dev", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-doc", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-mobile", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-modules", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-mp3", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-mysql", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-ooh323", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-voicemail", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-voicemail-imapstorage", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-voicemail-odbcstorage", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;
if (deb_check(release:"9.0", prefix:"asterisk-vpb", reference:"1:13.14.1~dfsg-2+deb9u4")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:deb_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
  • NASL familyMisc.
    NASL idASTERISK_AST_2018_002-005.NASL
    descriptionAccording to its SIP banner, the version of Asterisk running on the remote host is 13.x prior to 13.19.2, 14.x prior to 14.7.6, or 13.18 prior to 13.18-cert3. It is therefore, affected by a Multiple Denial of Service Vulnerabilities as described in AST-2018-002, AST-2018-003, AST-2018-004, & AST-2018-005 advisories. Note that Nessus has not tested for these issues but has instead relied only on the application
    last seen2020-06-01
    modified2020-06-02
    plugin id107101
    published2018-03-02
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/107101
    titleAsterisk 13.x < 13.19.2 / 14.x < 14.7.6 / 13.13 < 13.18-cert3 Multiple DoS Vulnerabilities (AST-2018-002, AST-2018-003, AST-2018-004, & AST-2018-005)
  • NASL familyMisc.
    NASL idASTERISK_AST_2018_001-006.NASL
    descriptionAccording to its SIP banner, the version of Asterisk running on the remote host is 15.x prior to 15.2.2. It is therefore, affected by multiple vulnerabilities as described in AST-2018-001, AST-2018-002, AST-2018-003, AST-2018-004, AST-2018-005, & AST-2018-006 advisories. Note that Nessus has not tested for these issues but has instead relied only on the application
    last seen2020-06-01
    modified2020-06-02
    plugin id107100
    published2018-03-02
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/107100
    titleAsterisk 15.x < 15.2.2 Multiple Vulnerabilities (AST-2018-001 - AST-2018-006)
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_933654CE17B811E890B8001999F8D30B.NASL
    descriptionThe Asterisk project reports : AST-2018-004 - When processing a SUBSCRIBE request the res_pjsip_pubsub module stores the accepted formats present in the Accept headers of the request. This code did not limit the number of headers it processed despite having a fixed limit of 32. If more than 32 Accept headers were present the code would write outside of its memory and cause a crash. AST-2018-005 - A crash occurs when a number of authenticated INVITE messages are sent over TCP or TLS and then the connection is suddenly closed. This issue leads to a segmentation fault.
    last seen2020-06-01
    modified2020-06-02
    plugin id106959
    published2018-02-23
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/106959
    titleFreeBSD : asterisk -- multiple vulnerabilities (933654ce-17b8-11e8-90b8-001999f8d30b)

Packetstorm

data sourcehttps://packetstormsecurity.com/files/download/146577/ES2018-01.txt
idPACKETSTORM:146577
last seen2018-02-27
published2018-02-26
reporterSandro Gauci
sourcehttps://packetstormsecurity.com/files/146577/Asterisk-15.2.0-chan_pjsip-SUBSCRIBE-Stack-Corruption.html
titleAsterisk 15.2.0 chan_pjsip SUBSCRIBE Stack Corruption

References