Vulnerabilities > CVE-2019-20454 - Out-of-bounds Read vulnerability in multiple products

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
network
low complexity
pcre
fedoraproject
splunk
CWE-125
nessus

Summary

An out-of-bounds read was discovered in PCRE before 10.34 when the pattern \X is JIT compiled and used to match specially crafted subjects in non-UTF mode. Applications that use PCRE to parse untrusted input may be vulnerable to this flaw, which would allow an attacker to crash the application. The flaw occurs in do_extuni_no_utf in pcre2_jit_compile.c.

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 familyHuawei Local Security Checks
NASL idEULEROS_SA-2020-1510.NASL
descriptionAccording to the version of the pcre2 packages installed, the EulerOS installation on the remote host is affected by the following vulnerability : - An out-of-bounds read was discovered in PCRE when the pattern
last seen2020-05-03
modified2020-04-20
plugin id135743
published2020-04-20
reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/135743
titleEulerOS 2.0 SP8 : pcre2 (EulerOS-SA-2020-1510)
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(135743);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/01");

  script_cve_id(
    "CVE-2019-20454"
  );

  script_name(english:"EulerOS 2.0 SP8 : pcre2 (EulerOS-SA-2020-1510)");
  script_summary(english:"Checks the rpm output for the updated package.");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"According to the version of the pcre2 packages installed, the EulerOS
installation on the remote host is affected by the following
vulnerability :

  - An out-of-bounds read was discovered in PCRE when the
    pattern '\X' is JIT compiled and used to match
    specially crafted subjects in non-UTF mode.
    Applications that use PCRE to process untrusted input
    may be vulnerable to this flaw. An attacker could use
    this flaw to crash the application.(CVE-2019-20454)

Note that Tenable Network Security has extracted the preceding
description block directly from the EulerOS security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2020-1510
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9c6f9951");
  script_set_attribute(attribute:"solution", value:
"Update the affected pcre2 package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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:N/AC:L/PR:N/UI:N/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:"patch_publication_date", value:"2020/04/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/04/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:pcre2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:pcre2-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:pcre2-utf16");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:pcre2-utf32");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:2.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Huawei Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/sp");
  script_exclude_keys("Host/EulerOS/uvp_version");

  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/EulerOS/release");
if (isnull(release) || release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
if (release !~ "^EulerOS release 2\.0(\D|$)") audit(AUDIT_OS_NOT, "EulerOS 2.0");

sp = get_kb_item("Host/EulerOS/sp");
if (isnull(sp) || sp !~ "^(8)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP8");

uvp = get_kb_item("Host/EulerOS/uvp_version");
if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP8", "EulerOS UVP " + uvp);

if (!get_kb_item("Host/EulerOS/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$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("aarch64" >!< cpu) audit(AUDIT_ARCH_NOT, "aarch64", cpu);

flag = 0;

pkgs = ["pcre2-10.32-3.h2.eulerosv2r8",
        "pcre2-devel-10.32-3.h2.eulerosv2r8",
        "pcre2-utf16-10.32-3.h2.eulerosv2r8",
        "pcre2-utf32-10.32-3.h2.eulerosv2r8"];

foreach (pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"8", reference:pkg)) 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, "pcre2");
}