Vulnerabilities > CVE-2012-6711 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in multiple products

047910
CVSS 7.8 - HIGH
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
local
low complexity
gnu
redhat
CWE-119
nessus
NVD
Published: 2019-06-18
Updated: 2023-11-07

Summary

A heap-based buffer overflow exists in GNU Bash before 4.3 when wide characters, not supported by the current locale set in the LC_CTYPE environment variable, are printed through the echo built-in function. A local attacker, who can provide data to print through the "echo -e" built-in function, may use this flaw to crash a script or execute code with the privileges of the bash process. This occurs because ansicstr() in lib/sh/strtrans.c mishandles u32cconv().

Vulnerable Configurations

Part Description Count
Application
Gnu
3
OS
Redhat
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.

Nessus

  • NASL familyPhotonOS Local Security Checks
    NASL idPHOTONOS_PHSA-2019-1_0-0255_BASH.NASL
    descriptionAn update of the bash package has been released.
    last seen2020-06-01
    modified2020-06-02
    plugin id129681
    published2019-10-07
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/129681
    titlePhoton OS 1.0: Bash PHSA-2019-1.0-0255
    code
    #
# (C) Tenable Network Security, Inc.
#

# The descriptive text and package checks in this plugin were
# extracted from VMware Security Advisory PHSA-2019-1.0-0255. The text
# itself is copyright (C) VMware, Inc.

include("compat.inc");

if (description)
{
  script_id(129681);
  script_version("1.2");
  script_cvs_date("Date: 2019/12/19");

  script_cve_id("CVE-2012-6711");

  script_name(english:"Photon OS 1.0: Bash PHSA-2019-1.0-0255");

  script_set_attribute(attribute:"synopsis", value:
"The remote PhotonOS host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"An update of the bash package has been released.");
  script_set_attribute(attribute:"see_also", value:"https://github.com/vmware/photon/wiki/Security-Updates-1.0-255.md");
  script_set_attribute(attribute:"solution", value:
"Update the affected Linux packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/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:L/AC:L/PR:L/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:"cvss_score_source", value:"CVE-2012-6711");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/06/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/10/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/10/07");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:vmware:photonos:bash");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:vmware:photonos:1.0");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/PhotonOS/release", "Host/PhotonOS/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/PhotonOS/release");
if (isnull(release) || release !~ "^VMware Photon") audit(AUDIT_OS_NOT, "PhotonOS");
if (release !~ "^VMware Photon (?:Linux|OS) 1\.0(\D|$)") audit(AUDIT_OS_NOT, "PhotonOS 1.0");

if (!get_kb_item("Host/PhotonOS/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, "PhotonOS", cpu);

flag = 0;

if (rpm_check(release:"PhotonOS-1.0", reference:"bash-4.3.48-4.ph1")) flag++;
if (rpm_check(release:"PhotonOS-1.0", reference:"bash-debuginfo-4.3.48-4.ph1")) flag++;
if (rpm_check(release:"PhotonOS-1.0", reference:"bash-lang-4.3.48-4.ph1")) 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, "bash");
}
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2019-1911.NASL
    descriptionAccording to the version of the bash package installed, the EulerOS installation on the remote host is affected by the following vulnerability : - A heap-based buffer overflow was discovered in bash when wide characters, not supported by the current locale set in LC_CTYPE environment variable, are printed through the echo built-in function. A local attacker, who can provide data to print through the `echo -e` built-in function, may use this flaw to crash a script or execute code with the privileges of the bash process.(CVE-2012-6711) 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.
    last seen2020-05-08
    modified2019-09-16
    plugin id128834
    published2019-09-16
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/128834
    titleEulerOS 2.0 SP5 : bash (EulerOS-SA-2019-1911)
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(128834);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/07");

  script_cve_id(
    "CVE-2012-6711"
  );

  script_name(english:"EulerOS 2.0 SP5 : bash (EulerOS-SA-2019-1911)");
  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 bash package installed, the EulerOS
installation on the remote host is affected by the following
vulnerability :

  - A heap-based buffer overflow was discovered in bash
    when wide characters, not supported by the current
    locale set in LC_CTYPE environment variable, are
    printed through the echo built-in function. A local
    attacker, who can provide data to print through the
    `echo -e` built-in function, may use this flaw to crash
    a script or execute code with the privileges of the
    bash process.(CVE-2012-6711)

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-2019-1911
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?36c57f2e");
  script_set_attribute(attribute:"solution", value:
"Update the affected bash package.");
  script_set_cvss_base_vector("CVSS2#AV:L/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:L/AC:L/PR:L/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:"patch_publication_date", value:"2019/09/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/09/16");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:bash");
  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) 2019-2020 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 !~ "^(5)$") audit(AUDIT_OS_NOT, "EulerOS 2.0 SP5");

uvp = get_kb_item("Host/EulerOS/uvp_version");
if (!empty_or_null(uvp)) audit(AUDIT_OS_NOT, "EulerOS 2.0 SP5", "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$" && "aarch64" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

flag = 0;

pkgs = ["bash-4.2.46-30.h8.eulerosv2r7"];

foreach (pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", sp:"5", 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, "bash");
}
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2019-2976-1.NASL
    descriptionThis update for bash fixes the following issues : CVE-2012-6711: Fixed a heap-based buffer overflow during echo of unsupported characters (bsc#1138676). Note that Tenable Network Security has extracted the preceding description block directly from the SUSE 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 id131071
    published2019-11-15
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/131071
    titleSUSE SLES12 Security Update : bash (SUSE-SU-2019:2976-1)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from SUSE update advisory SUSE-SU-2019:2976-1.
# The text itself is copyright (C) SUSE.
#

include("compat.inc");

if (description)
{
  script_id(131071);
  script_version("1.2");
  script_cvs_date("Date: 2019/12/12");

  script_cve_id("CVE-2012-6711");

  script_name(english:"SUSE SLES12 Security Update : bash (SUSE-SU-2019:2976-1)");
  script_summary(english:"Checks rpm output for the updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote SUSE host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"This update for bash fixes the following issues :

CVE-2012-6711: Fixed a heap-based buffer overflow during echo of
unsupported characters (bsc#1138676).

Note that Tenable Network Security has extracted the preceding
description block directly from the SUSE 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://bugzilla.suse.com/show_bug.cgi?id=1138676"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2012-6711/"
  );
  # https://www.suse.com/support/update/announcement/2019/suse-su-20192976-1/
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?1fba2497"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"To install this SUSE Security Update use the SUSE recommended
installation methods like YaST online_update or 'zypper patch'.

Alternatively you can run the command listed for your product :

SUSE Linux Enterprise Server for SAP 12-SP1:zypper in -t patch
SUSE-SLE-SAP-12-SP1-2019-2976=1

SUSE Linux Enterprise Server 12-SP1-LTSS:zypper in -t patch
SUSE-SLE-SERVER-12-SP1-2019-2976=1"
  );
  script_set_cvss_base_vector("CVSS2#AV:L/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:L/AC:L/PR:L/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:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:bash");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:bash-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:bash-debugsource");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:libreadline6");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:libreadline6-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:suse_linux:12");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/06/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/11/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/11/15");
  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 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"SuSE Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/cpu", "Host/SuSE/release", "Host/SuSE/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/SuSE/release");
if (isnull(release) || release !~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "SUSE");
os_ver = pregmatch(pattern: "^(SLE(S|D)\d+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "SUSE");
os_ver = os_ver[1];
if (! preg(pattern:"^(SLES12)$", string:os_ver)) audit(AUDIT_OS_NOT, "SUSE SLES12", "SUSE " + os_ver);

if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if (cpu !~ "^i[3-6]86$" && "x86_64" >!< cpu && "s390x" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "SUSE " + os_ver, cpu);

sp = get_kb_item("Host/SuSE/patchlevel");
if (isnull(sp)) sp = "0";
if (os_ver == "SLES12" && (! preg(pattern:"^(1)$", string:sp))) audit(AUDIT_OS_NOT, "SLES12 SP1", os_ver + " SP" + sp);


flag = 0;
if (rpm_check(release:"SLES12", sp:"1", reference:"bash-4.2-83.6.1")) flag++;
if (rpm_check(release:"SLES12", sp:"1", reference:"bash-debuginfo-4.2-83.6.1")) flag++;
if (rpm_check(release:"SLES12", sp:"1", reference:"bash-debugsource-4.2-83.6.1")) flag++;
if (rpm_check(release:"SLES12", sp:"1", reference:"libreadline6-6.2-83.6.1")) flag++;
if (rpm_check(release:"SLES12", sp:"1", reference:"libreadline6-debuginfo-6.2-83.6.1")) flag++;
if (rpm_check(release:"SLES12", sp:"1", reference:"libreadline6-32bit-6.2-83.6.1")) flag++;
if (rpm_check(release:"SLES12", sp:"1", reference:"libreadline6-debuginfo-32bit-6.2-83.6.1")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "bash");
}
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2019-1942.NASL
    descriptionAccording to the version of the bash package installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerability : - A heap-based buffer overflow was discovered in bash when wide characters, not supported by the current locale set in LC_CTYPE environment variable, are printed through the echo built-in function. A local attacker, who can provide data to print through the `echo -e` built-in function, may use this flaw to crash a script or execute code with the privileges of the bash process.(CVE-2012-6711) 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.
    last seen2020-06-01
    modified2020-06-02
    plugin id128945
    published2019-09-17
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/128945
    titleEulerOS Virtualization for ARM 64 3.0.2.0 : bash (EulerOS-SA-2019-1942)
  • NASL familyPhotonOS Local Security Checks
    NASL idPHOTONOS_PHSA-2019-1_0-0252_BASH.NASL
    descriptionAn update of the bash package has been released.
    last seen2020-06-01
    modified2020-06-02
    plugin id129783
    published2019-10-11
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/129783
    titlePhoton OS 1.0: Bash PHSA-2019-1.0-0252

References