Vulnerabilities > CVE-2014-8240 - Improper Restriction of Operations Within the Bounds of A Memory Buffer vulnerability in Tigervnc

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
tigervnc
CWE-119
nessus

Summary

Integer overflow in TigerVNC allows remote VNC servers to cause a denial of service (crash) and possibly execute arbitrary code via vectors related to screen size handling, which triggers a heap-based buffer overflow, a similar issue to CVE-2014-6051.

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 familyRed Hat Local Security Checks
    NASL idREDHAT-RHSA-2015-2233.NASL
    descriptionUpdated tigervnc packages that fix two security issues, several bugs, and add various enhancements are now available for Red Hat Enterprise Linux 7. Red Hat Product Security has rated this update as having Moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section. Virtual Network Computing (VNC) is a remote display system which allows users to view a computing desktop environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. TigerVNC is a suite of VNC servers and clients. The tigervnc packages contain a client which allows users to connect to other desktops running a VNC server. An integer overflow flaw, leading to a heap-based buffer overflow, was found in the way TigerVNC handled screen sizes. A malicious VNC server could use this flaw to cause a client to crash or, potentially, execute arbitrary code on the client. (CVE-2014-8240) A NULL pointer dereference flaw was found in TigerVNC
    last seen2020-06-01
    modified2020-06-02
    plugin id86976
    published2015-11-20
    reporterThis script is Copyright (C) 2015-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/86976
    titleRHEL 7 : tigervnc (RHSA-2015:2233)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Red Hat Security Advisory RHSA-2015:2233. The text 
    # itself is copyright (C) Red Hat, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(86976);
      script_version("2.12");
      script_cvs_date("Date: 2019/10/24 15:35:40");
    
      script_cve_id("CVE-2014-8240", "CVE-2014-8241");
      script_xref(name:"RHSA", value:"2015:2233");
    
      script_name(english:"RHEL 7 : tigervnc (RHSA-2015:2233)");
      script_summary(english:"Checks the rpm output for the updated packages");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote Red Hat host is missing one or more security updates."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "Updated tigervnc packages that fix two security issues, several bugs,
    and add various enhancements are now available for Red Hat Enterprise
    Linux 7.
    
    Red Hat Product Security has rated this update as having Moderate
    security impact. Common Vulnerability Scoring System (CVSS) base
    scores, which give detailed severity ratings, are available for each
    vulnerability from the CVE links in the References section.
    
    Virtual Network Computing (VNC) is a remote display system which
    allows users to view a computing desktop environment not only on the
    machine where it is running, but from anywhere on the Internet and
    from a wide variety of machine architectures. TigerVNC is a suite of
    VNC servers and clients. The tigervnc packages contain a client which
    allows users to connect to other desktops running a VNC server.
    
    An integer overflow flaw, leading to a heap-based buffer overflow, was
    found in the way TigerVNC handled screen sizes. A malicious VNC server
    could use this flaw to cause a client to crash or, potentially,
    execute arbitrary code on the client. (CVE-2014-8240)
    
    A NULL pointer dereference flaw was found in TigerVNC's XRegion. A
    malicious VNC server could use this flaw to cause a client to crash.
    (CVE-2014-8241)
    
    The tigervnc packages have been upgraded to upstream version 1.3.1,
    which provides a number of bug fixes and enhancements over the
    previous version. (BZ#1199453)
    
    This update also fixes the following bug :
    
    * The position of the mouse cursor in the VNC session was not
    correctly communicated to the VNC viewer, resulting in cursor
    misplacement. The method of displaying the remote cursor has been
    changed, and cursor movements on the VNC server are now accurately
    reflected on the VNC client. (BZ#1100661)
    
    All tigervnc users are advised to upgrade to these updated packages,
    which correct these issues and add these enhancements."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://access.redhat.com/errata/RHSA-2015:2233"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://access.redhat.com/security/cve/cve-2014-8240"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://access.redhat.com/security/cve/cve-2014-8241"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected packages.");
      script_set_cvss_base_vector("CVSS2#AV:N/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:N/AC:L/PR:N/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:"exploit_available", value:"false");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:tigervnc");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:tigervnc-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:tigervnc-icons");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:tigervnc-license");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:tigervnc-server");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:tigervnc-server-applet");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:tigervnc-server-minimal");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:tigervnc-server-module");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.2");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.3");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.4");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.5");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.6");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.7");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2014/10/16");
      script_set_attribute(attribute:"patch_publication_date", value:"2015/11/19");
      script_set_attribute(attribute:"plugin_publication_date", value:"2015/11/20");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2015-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"Red Hat Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/cpu");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("global_settings.inc");
    include("misc_func.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) || "Red Hat" >!< release) audit(AUDIT_OS_NOT, "Red Hat");
    os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:release);
    if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Red Hat");
    os_ver = os_ver[1];
    if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Red Hat 7.x", "Red Hat " + 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$" && "s390" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Red Hat", cpu);
    
    yum_updateinfo = get_kb_item("Host/RedHat/yum-updateinfo");
    if (!empty_or_null(yum_updateinfo)) 
    {
      rhsa = "RHSA-2015:2233";
      yum_report = redhat_generate_yum_updateinfo_report(rhsa:rhsa);
      if (!empty_or_null(yum_report))
      {
        security_report_v4(
          port       : 0,
          severity   : SECURITY_HOLE,
          extra      : yum_report 
        );
        exit(0);
      }
      else
      {
        audit_message = "affected by Red Hat security advisory " + rhsa;
        audit(AUDIT_OS_NOT, audit_message);
      }
    }
    else
    {
      flag = 0;
      if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"tigervnc-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"tigervnc-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"tigervnc-debuginfo-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"tigervnc-debuginfo-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", reference:"tigervnc-icons-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", reference:"tigervnc-license-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"tigervnc-server-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"tigervnc-server-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", reference:"tigervnc-server-applet-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"tigervnc-server-minimal-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"tigervnc-server-minimal-1.3.1-3.el7")) flag++;
    
      if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"tigervnc-server-module-1.3.1-3.el7")) flag++;
    
    
      if (flag)
      {
        security_report_v4(
          port       : 0,
          severity   : SECURITY_HOLE,
          extra      : rpm_report_get() + redhat_report_package_caveat()
        );
        exit(0);
      }
      else
      {
        tested = pkg_tests_get();
        if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
        else audit(AUDIT_PACKAGE_NOT_INSTALLED, "tigervnc / tigervnc-debuginfo / tigervnc-icons / tigervnc-license / etc");
      }
    }
    
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2014-1592-1.NASL
    descriptionThis update for tigervnc provides the following fixes : - Fixed integer overflow flaw, leading to a heap-based buffer overflow in screen size handling. (CVE-2014-8240) - Send correctly keys that don
    last seen2020-06-05
    modified2015-05-20
    plugin id83649
    published2015-05-20
    reporterThis script is Copyright (C) 2015-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/83649
    titleSUSE SLED12 / SLES12 Security Update : tigervnc (SUSE-SU-2014:1592-1)
  • NASL familyAmazon Linux Local Security Checks
    NASL idALA_ALAS-2015-623.NASL
    descriptionAn integer overflow flaw, leading to a heap-based buffer overflow, was found in the way TigerVNC handled screen sizes. A malicious VNC server could use this flaw to cause a client to crash or, potentially, execute arbitrary code on the client. A NULL pointer dereference flaw was found in TigerVNC
    last seen2020-06-01
    modified2020-06-02
    plugin id87349
    published2015-12-15
    reporterThis script is Copyright (C) 2015-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/87349
    titleAmazon Linux AMI : tigervnc (ALAS-2015-623)
  • NASL familyScientific Linux Local Security Checks
    NASL idSL_20151119_TIGERVNC_ON_SL7_X.NASL
    descriptionAn integer overflow flaw, leading to a heap-based buffer overflow, was found in the way TigerVNC handled screen sizes. A malicious VNC server could use this flaw to cause a client to crash or, potentially, execute arbitrary code on the client. (CVE-2014-8240) A NULL pointer dereference flaw was found in TigerVNC
    last seen2020-03-18
    modified2015-12-22
    plugin id87576
    published2015-12-22
    reporterThis script is Copyright (C) 2015-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/87576
    titleScientific Linux Security Update : tigervnc on SL7.x x86_64 (20151119)
  • NASL familyOracle Linux Local Security Checks
    NASL idORACLELINUX_ELSA-2015-2233.NASL
    descriptionFrom Red Hat Security Advisory 2015:2233 : Updated tigervnc packages that fix two security issues, several bugs, and add various enhancements are now available for Red Hat Enterprise Linux 7. Red Hat Product Security has rated this update as having Moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section. Virtual Network Computing (VNC) is a remote display system which allows users to view a computing desktop environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. TigerVNC is a suite of VNC servers and clients. The tigervnc packages contain a client which allows users to connect to other desktops running a VNC server. An integer overflow flaw, leading to a heap-based buffer overflow, was found in the way TigerVNC handled screen sizes. A malicious VNC server could use this flaw to cause a client to crash or, potentially, execute arbitrary code on the client. (CVE-2014-8240) A NULL pointer dereference flaw was found in TigerVNC
    last seen2020-06-01
    modified2020-06-02
    plugin id87093
    published2015-11-30
    reporterThis script is Copyright (C) 2015-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/87093
    titleOracle Linux 7 : tigervnc (ELSA-2015-2233)
  • NASL familyGentoo Local Security Checks
    NASL idGENTOO_GLSA-201612-36.NASL
    descriptionThe remote host is affected by the vulnerability described in GLSA-201612-36 (TigerVNC: Integer overflow) TigerVNC is impacted by the same vulnerability as found in CVE-2014-6051. An integer overflow, leading to a heap-based buffer overflow, was found in the way screen sizes were handled. Impact : A remote attacker, utilizing a malicious VNC server, could execute arbitrary code with the privileges of the user running the client, or cause a Denial of Service condition. Workaround : There is no known workaround at this time.
    last seen2020-06-01
    modified2020-06-02
    plugin id95739
    published2016-12-13
    reporterThis script is Copyright (C) 2016 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/95739
    titleGLSA-201612-36 : TigerVNC: Integer overflow
  • NASL familyCentOS Local Security Checks
    NASL idCENTOS_RHSA-2015-2233.NASL
    descriptionUpdated tigervnc packages that fix two security issues, several bugs, and add various enhancements are now available for Red Hat Enterprise Linux 7. Red Hat Product Security has rated this update as having Moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section. Virtual Network Computing (VNC) is a remote display system which allows users to view a computing desktop environment not only on the machine where it is running, but from anywhere on the Internet and from a wide variety of machine architectures. TigerVNC is a suite of VNC servers and clients. The tigervnc packages contain a client which allows users to connect to other desktops running a VNC server. An integer overflow flaw, leading to a heap-based buffer overflow, was found in the way TigerVNC handled screen sizes. A malicious VNC server could use this flaw to cause a client to crash or, potentially, execute arbitrary code on the client. (CVE-2014-8240) A NULL pointer dereference flaw was found in TigerVNC
    last seen2020-06-01
    modified2020-06-02
    plugin id87144
    published2015-12-02
    reporterThis script is Copyright (C) 2015-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/87144
    titleCentOS 7 : tigervnc (CESA-2015:2233)

Redhat

rpms
  • tigervnc-0:1.3.1-3.el7
  • tigervnc-debuginfo-0:1.3.1-3.el7
  • tigervnc-icons-0:1.3.1-3.el7
  • tigervnc-license-0:1.3.1-3.el7
  • tigervnc-server-0:1.3.1-3.el7
  • tigervnc-server-applet-0:1.3.1-3.el7
  • tigervnc-server-minimal-0:1.3.1-3.el7
  • tigervnc-server-module-0:1.3.1-3.el7