Vulnerabilities > CVE-2019-9721 - Out-of-bounds Read vulnerability in multiple products

047910
CVSS 6.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
network
low complexity
ffmpeg
canonical
CWE-125
nessus
NVD
Published: 2019-03-12
Updated: 2022-10-07

Summary

A denial of service in the subtitle decoder in FFmpeg 3.2 and 4.1 allows attackers to hog the CPU via a crafted video file in Matroska format, because handle_open_brace in libavcodec/htmlsubtitles.c has a complex format argument to sscanf.

Vulnerable Configurations

Part Description Count
Application
Ffmpeg
2
OS
Canonical
3

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Overread Buffers
    An adversary attacks a target by providing input that causes an application to read beyond the boundary of a defined buffer. This typically occurs when a value influencing where to start or stop reading is set to reflect positions outside of the valid memory location of the buffer. This type of attack may result in exposure of sensitive information, a system crash, or arbitrary code execution.

Nessus

NASL familyUbuntu Local Security Checks
NASL idUBUNTU_USN-3967-1.NASL
descriptionIt was discovered that FFmpeg contained multiple security issues when handling certain multimedia files. If a user were tricked into opening a crafted multimedia file, an attacker could cause a denial of service via application crash. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
last seen2020-06-01
modified2020-06-02
plugin id124678
published2019-05-07
reporterUbuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/124678
titleUbuntu 18.04 LTS / 18.10 / 19.04 : FFmpeg vulnerabilities (USN-3967-1)
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3967-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include("compat.inc");

if (description)
{
  script_id(124678);
  script_version("1.3");
  script_cvs_date("Date: 2020/01/21");

  script_cve_id("CVE-2018-15822", "CVE-2019-11338", "CVE-2019-11339", "CVE-2019-9718", "CVE-2019-9721");
  script_xref(name:"USN", value:"3967-1");

  script_name(english:"Ubuntu 18.04 LTS / 18.10 / 19.04 : FFmpeg vulnerabilities (USN-3967-1)");
  script_summary(english:"Checks dpkg output for updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Ubuntu host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"It was discovered that FFmpeg contained multiple security issues when
handling certain multimedia files. If a user were tricked into opening
a crafted multimedia file, an attacker could cause a denial of service
via application crash.

Note that Tenable Network Security has extracted the preceding
description block directly from the Ubuntu 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://usn.ubuntu.com/3967-1/"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/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:R/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:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ffmpeg");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavcodec-extra57");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavcodec-extra58");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavcodec57");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavcodec58");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavdevice57");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavdevice58");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavfilter-extra6");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavfilter-extra7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavfilter6");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavfilter7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavformat57");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavformat58");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavresample3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavresample4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavutil55");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavutil56");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpostproc54");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpostproc55");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libswresample2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libswresample3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libswscale4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libswscale5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:19.04");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/08/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/05/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/05/07");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Ubuntu Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("misc_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/Ubuntu/release");
if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
release = chomp(release);
if (! preg(pattern:"^(18\.04|18\.10|19\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 18.04 / 18.10 / 19.04", "Ubuntu " + release);
if ( ! get_kb_item("Host/Debian/dpkg-l") ) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Ubuntu", cpu);

flag = 0;

if (ubuntu_check(osver:"18.04", pkgname:"ffmpeg", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libavcodec-extra57", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libavcodec57", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libavdevice57", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libavfilter-extra6", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libavfilter6", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libavformat57", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libavresample3", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libavutil55", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libpostproc54", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libswresample2", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libswscale4", pkgver:"7:3.4.6-0ubuntu0.18.04.1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"ffmpeg", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libavcodec-extra58", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libavcodec58", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libavdevice58", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libavfilter-extra7", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libavfilter7", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libavformat58", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libavresample4", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libavutil56", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libpostproc55", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libswresample3", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libswscale5", pkgver:"7:4.0.4-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"ffmpeg", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libavcodec-extra58", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libavcodec58", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libavdevice58", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libavfilter-extra7", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libavfilter7", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libavformat58", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libavresample4", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libavutil56", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libpostproc55", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libswresample3", pkgver:"7:4.1.3-0ubuntu1")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libswscale5", pkgver:"7:4.1.3-0ubuntu1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "ffmpeg / libavcodec-extra57 / libavcodec-extra58 / libavcodec57 / etc");
}

References