Vulnerabilities > CVE-2018-11503 - Out-of-bounds Read vulnerability in multiple products

047910
CVSS 4.3 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
PARTIAL
network
discount-project
debian
CWE-125
nessus
NVD
Published: 2018-05-26
Updated: 2019-10-03

Summary

The isfootnote function in markdown.c in libmarkdown.a in DISCOUNT 2.2.3a allows remote attackers to cause a denial of service (heap-based buffer over-read) via a crafted file, as demonstrated by mkd2html.

Vulnerable Configurations

Part Description Count
Application
Discount_Project
1
OS
Debian
2

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 familyFedora Local Security Checks
    NASL idFEDORA_2018-38BDBAFA96.NASL
    descriptionUpstream version 2.2.4 Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-06-05
    modified2019-01-03
    plugin id120354
    published2019-01-03
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120354
    titleFedora 28 : discount (2018-38bdbafa96)
    code
    #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory FEDORA-2018-38bdbafa96.
#

include("compat.inc");

if (description)
{
  script_id(120354);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");

  script_cve_id("CVE-2018-11468", "CVE-2018-11503", "CVE-2018-11504", "CVE-2018-12495");
  script_xref(name:"FEDORA", value:"2018-38bdbafa96");

  script_name(english:"Fedora 28 : discount (2018-38bdbafa96)");
  script_summary(english:"Checks rpm output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Fedora host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Upstream version 2.2.4

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora update system website.
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://bodhi.fedoraproject.org/updates/FEDORA-2018-38bdbafa96"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected discount package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/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:fedoraproject:fedora:discount");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:28");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/05/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/09/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/01/03");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Fedora Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! preg(pattern:"^28([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 28", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) 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, "Fedora", cpu);


flag = 0;
if (rpm_check(release:"FC28", reference:"discount-2.2.4-1.fc28")) flag++;


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "discount");
}
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DLA-1499.NASL
    descriptionSeveral heap-based buffer over-reads were found in discount, an implementation of the Markdown markup language in C, that allowed remote attackers to cause a denial of service via specially crafted files. For Debian 8
    last seen2020-06-01
    modified2020-06-02
    plugin id117367
    published2018-09-10
    reporterThis script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/117367
    titleDebian DLA-1499-1 : discount security update
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-1499-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(117367);
  script_version("1.1");
  script_cvs_date("Date: 2018/09/10 11:37:03");

  script_cve_id("CVE-2018-11468", "CVE-2018-11503", "CVE-2018-11504", "CVE-2018-12495");

  script_name(english:"Debian DLA-1499-1 : discount 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:
"Several heap-based buffer over-reads were found in discount, an
implementation of the Markdown markup language in C, that allowed
remote attackers to cause a denial of service via specially crafted
files.

For Debian 8 'Jessie', these problems have been fixed in version
2.1.7-1+deb8u1.

We recommend that you upgrade your discount 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/2018/09/msg00009.html"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/jessie/discount"
  );
  script_set_attribute(attribute:"solution", value:"Upgrade the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:discount");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libmarkdown2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libmarkdown2-dbg");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libmarkdown2-dev");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/09/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/09/10");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 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:"discount", reference:"2.1.7-1+deb8u1")) flag++;
if (deb_check(release:"8.0", prefix:"libmarkdown2", reference:"2.1.7-1+deb8u1")) flag++;
if (deb_check(release:"8.0", prefix:"libmarkdown2-dbg", reference:"2.1.7-1+deb8u1")) flag++;
if (deb_check(release:"8.0", prefix:"libmarkdown2-dev", reference:"2.1.7-1+deb8u1")) 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 familyDebian Local Security Checks
    NASL idDEBIAN_DSA-4293.NASL
    descriptionSeveral heap buffer overflows were found in discount, an implementation of the Markdown markup language, that could be triggered with specially crafted Markdown data and would cause discount to read past the end of internal buffers.
    last seen2020-06-01
    modified2020-06-02
    plugin id117503
    published2018-09-17
    reporterThis script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/117503
    titleDebian DSA-4293-1 : discount - security update
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Debian Security Advisory DSA-4293. The text 
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(117503);
  script_version("1.3");
  script_cvs_date("Date: 2018/11/13 12:30:47");

  script_cve_id("CVE-2018-11468", "CVE-2018-11503", "CVE-2018-11504", "CVE-2018-12495");
  script_xref(name:"DSA", value:"4293");

  script_name(english:"Debian DSA-4293-1 : discount - 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:
"Several heap buffer overflows were found in discount, an
implementation of the Markdown markup language, that could be
triggered with specially crafted Markdown data and would cause
discount to read past the end of internal buffers."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=901912"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://security-tracker.debian.org/tracker/source-package/discount"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/stretch/discount"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.debian.org/security/2018/dsa-4293"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Upgrade the discount packages.

For the stable distribution (stretch), these problems have been fixed
in version 2.2.2-1+deb9u1."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:discount");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/09/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/09/17");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 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:"9.0", prefix:"discount", reference:"2.2.2-1+deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libmarkdown2", reference:"2.2.2-1+deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libmarkdown2-dev", reference:"2.2.2-1+deb9u1")) 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");

References