Vulnerabilities > CVE-2017-16611 - Link Following vulnerability in multiple products

047910
CVSS 5.5 - MEDIUM
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
local
low complexity
debian
canonical
x
CWE-59
nessus

Summary

In libXfont before 1.5.4 and libXfont2 before 2.0.3, a local attacker can open (but not read) files on the system as root, triggering tape rewinds, watchdogs, or similar mechanisms that can be triggered by opening files.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Symlink Attack
    An attacker positions a symbolic link in such a manner that the targeted user or application accesses the link's endpoint, assuming that it is accessing a file with the link's name. The endpoint file may be either output or input. If the file is output, the result is that the endpoint is modified, instead of a file at the intended location. Modifications to the endpoint file may include appending, overwriting, corrupting, changing permissions, or other modifications. In some variants of this attack the attacker may be able to control the change to a file while in other cases they cannot. The former is especially damaging since the attacker may be able to grant themselves increased privileges or insert false information, but the latter can also be damaging as it can expose sensitive information or corrupt or destroy vital system or application files. Alternatively, the endpoint file may serve as input to the targeted application. This can be used to feed malformed input into the target or to cause the target to process different information, possibly allowing the attacker to control the actions of the target or to cause the target to expose information to the attacker. Moreover, the actions taken on the endpoint file are undertaken with the permissions of the targeted user or application, which may exceed the permissions that the attacker would normally have.
  • Accessing, Modifying or Executing Executable Files
    An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
  • Leverage Executable Code in Non-Executable Files
    An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.

Nessus

  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-05B078C373.NASL
    descriptionSecurity fix for CVE-2017-16611 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
    modified2018-03-07
    plugin id107154
    published2018-03-07
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/107154
    titleFedora 26 : libXfont2 (2018-05b078c373)
    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-2018-05b078c373.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(107154);
      script_version("1.3");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");
    
      script_cve_id("CVE-2017-16611");
      script_xref(name:"FEDORA", value:"2018-05b078c373");
    
      script_name(english:"Fedora 26 : libXfont2 (2018-05b078c373)");
      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:
    "Security fix for CVE-2017-16611
    
    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-2018-05b078c373"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Update the affected libXfont2 package."
      );
      script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:P");
      script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/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:fedoraproject:fedora:libXfont2");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:26");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2017/12/01");
      script_set_attribute(attribute:"patch_publication_date", value:"2018/03/06");
      script_set_attribute(attribute:"plugin_publication_date", value:"2018/03/07");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2018-2020 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:"^26([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 26", "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:"FC26", reference:"libXfont2-2.0.3-1.fc26")) flag++;
    
    
    if (flag)
    {
      security_report_v4(
        port       : 0,
        severity   : SECURITY_NOTE,
        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, "libXfont2");
    }
    
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2019-2625.NASL
    descriptionAccording to the versions of the libXfont package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities : - In libXfont before 1.5.4 and libXfont2 before 2.0.3, a local attacker can open (but not read) files on the system as root, triggering tape rewinds, watchdogs, or similar mechanisms that can be triggered by opening files.(CVE-2017-16611) - In the PatternMatch function in fontfile/fontdir.c in libXfont through 1.5.2 and 2.x before 2.0.2, an attacker with access to an X connection can cause a buffer over-read during pattern matching of fonts, leading to information disclosure or a crash (denial of service). This occurs because
    last seen2020-05-08
    modified2019-12-18
    plugin id132160
    published2019-12-18
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/132160
    titleEulerOS 2.0 SP3 : libXfont (EulerOS-SA-2019-2625)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-4F5A3E792F.NASL
    descriptionSecurity fix for CVE-2017-16611 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
    modified2018-03-07
    plugin id107164
    published2018-03-07
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/107164
    titleFedora 27 : libXfont2 (2018-4f5a3e792f)
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2019-2357.NASL
    descriptionAccording to the versions of the libXfont package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities : - The LZW decompressor in (1) the BufCompressedFill function in fontfile/decompress.c in X.Org libXfont before 1.4.4 and (2) compress/compress.c in 4.3BSD, as used in zopen.c in OpenBSD before 3.8, FreeBSD, NetBSD 4.0.x and 5.0.x before 5.0.3 and 5.1.x before 5.1.1, FreeType 2.1.9, and other products, does not properly handle code words that are absent from the decompression table when encountered, which allows context-dependent attackers to trigger an infinite loop or a heap-based buffer overflow, and possibly execute arbitrary code, via a crafted compressed stream, a related issue to CVE-2006-1168 and CVE-2011-2896.(CVE-2011-2895) - In the pcfGetProperties function in bitmap/pcfread.c in libXfont through 1.5.2 and 2.x before 2.0.2, a missing boundary check (for PCF files) could be used by local attackers authenticated to an Xserver for a buffer over-read, for information disclosure or a crash of the X server.(CVE-2017-13722) - In the PatternMatch function in fontfile/fontdir.c in libXfont through 1.5.2 and 2.x before 2.0.2, an attacker with access to an X connection can cause a buffer over-read during pattern matching of fonts, leading to information disclosure or a crash (denial of service). This occurs because
    last seen2020-05-08
    modified2019-12-10
    plugin id131849
    published2019-12-10
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/131849
    titleEulerOS 2.0 SP2 : libXfont (EulerOS-SA-2019-2357)
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2020-1459.NASL
    descriptionAccording to the versions of the libXfont package installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities : - In libXfont before 1.5.4 and libXfont2 before 2.0.3, a local attacker can open (but not read) files on the system as root, triggering tape rewinds, watchdogs, or similar mechanisms that can be triggered by opening files.(CVE-2017-16611) - In the pcfGetProperties function in bitmap/pcfread.c in libXfont through 1.5.2 and 2.x before 2.0.2, a missing boundary check (for PCF files) could be used by local attackers authenticated to an Xserver for a buffer over-read, for information disclosure or a crash of the X server.(CVE-2017-13722) - In the PatternMatch function in fontfile/fontdir.c in libXfont through 1.5.2 and 2.x before 2.0.2, an attacker with access to an X connection can cause a buffer over-read during pattern matching of fonts, leading to information disclosure or a crash (denial of service). This occurs because
    last seen2020-04-30
    modified2020-04-16
    plugin id135621
    published2020-04-16
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/135621
    titleEulerOS Virtualization 3.0.2.2 : libXfont (EulerOS-SA-2020-1459)
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_08A125F3E35A11E7A29354E1AD3D6335.NASL
    descriptionthe freedesktop.org project reports : A non-privileged X client can instruct X server running under root to open any file by creating own directory with
    last seen2020-06-01
    modified2020-06-02
    plugin id105335
    published2017-12-18
    reporterThis script is Copyright (C) 2017-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/105335
    titleFreeBSD : libXfont -- permission bypass when opening files through symlinks (08a125f3-e35a-11e7-a293-54e1ad3d6335)
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2020-1241.NASL
    descriptionAccording to the versions of the libXfont package installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerabilities : - In libXfont before 1.5.4 and libXfont2 before 2.0.3, a local attacker can open (but not read) files on the system as root, triggering tape rewinds, watchdogs, or similar mechanisms that can be triggered by opening files.(CVE-2017-16611) - In the pcfGetProperties function in bitmap/pcfread.c in libXfont through 1.5.2 and 2.x before 2.0.2, a missing boundary check (for PCF files) could be used by local attackers authenticated to an Xserver for a buffer over-read, for information disclosure or a crash of the X server.(CVE-2017-13722) - In the PatternMatch function in fontfile/fontdir.c in libXfont through 1.5.2 and 2.x before 2.0.2, an attacker with access to an X connection can cause a buffer over-read during pattern matching of fonts, leading to information disclosure or a crash (denial of service). This occurs because
    last seen2020-03-19
    modified2020-03-13
    plugin id134530
    published2020-03-13
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/134530
    titleEulerOS Virtualization for ARM 64 3.0.2.0 : libXfont (EulerOS-SA-2020-1241)
  • NASL familySlackware Local Security Checks
    NASL idSLACKWARE_SSA_2017-333-02.NASL
    descriptionNew libXfont packages are available for Slackware 13.0, 13.1, 13.37, 14.0, 14.1, and 14.2 to fix a security issue.
    last seen2020-06-01
    modified2020-06-02
    plugin id104859
    published2017-11-30
    reporterThis script is Copyright (C) 2017-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/104859
    titleSlackware 13.0 / 13.1 / 13.37 / 14.0 / 14.1 / 14.2 : libXfont (SSA:2017-333-02)
  • NASL familyGentoo Local Security Checks
    NASL idGENTOO_GLSA-201801-10.NASL
    descriptionThe remote host is affected by the vulnerability described in GLSA-201801-10 (LibXfont, LibXfont2: Arbitrary file access) It was discovered that libXfont incorrectly followed symlinks when opening font files. Impact : A local unprivileged user could use this flaw to cause the X server to access arbitrary files, including special device files. Workaround : There is no known workaround at this time.
    last seen2020-06-01
    modified2020-06-02
    plugin id105666
    published2018-01-09
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/105666
    titleGLSA-201801-10 : LibXfont, LibXfont2: Arbitrary file access
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2019-2172.NASL
    descriptionAccording to the version of the libXfont package installed, the EulerOS installation on the remote host is affected by the following vulnerability : - In libXfont before 1.5.4 and libXfont2 before 2.0.3, a local attacker can open (but not read) files on the system as root, triggering tape rewinds, watchdogs, or similar mechanisms that can be triggered by opening files.(CVE-2017-16611) 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
    modified2019-11-12
    plugin id130881
    published2019-11-12
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/130881
    titleEulerOS 2.0 SP5 : libXfont (EulerOS-SA-2019-2172)
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-3500-1.NASL
    descriptionIt was discovered that libXfont incorrectly followed symlinks when opening font files. A local unprivileged user could use this issue to cause the X server to access arbitrary files, including special device files. 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 id104883
    published2017-11-30
    reporterUbuntu Security Notice (C) 2017-2019 Canonical, Inc. / NASL script (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/104883
    titleUbuntu 14.04 LTS / 16.04 LTS / 17.04 / 17.10 : libxfont, libxfont1, libxfont2 vulnerability (USN-3500-1)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-5A7CD68500.NASL
    descriptionSecurity fix for CVE-2017-16611 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
    modified2018-03-07
    plugin id107167
    published2018-03-07
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/107167
    titleFedora 26 : libXfont (2018-5a7cd68500)
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2020-1242.NASL
    descriptionAccording to the version of the libXfont2 package installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerability : - In libXfont before 1.5.4 and libXfont2 before 2.0.3, a local attacker can open (but not read) files on the system as root, triggering tape rewinds, watchdogs, or similar mechanisms that can be triggered by opening files.(CVE-2017-16611) 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 seen2020-03-19
    modified2020-03-13
    plugin id134531
    published2020-03-13
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/134531
    titleEulerOS Virtualization for ARM 64 3.0.2.0 : libXfont2 (EulerOS-SA-2020-1242)
  • NASL familyHuawei Local Security Checks
    NASL idEULEROS_SA-2019-2347.NASL
    descriptionAccording to the version of the libXfont2 package installed, the EulerOS Virtualization for ARM 64 installation on the remote host is affected by the following vulnerability : - In libXfont before 1.5.4 and libXfont2 before 2.0.3, a local attacker can open (but not read) files on the system as root, triggering tape rewinds, watchdogs, or similar mechanisms that can be triggered by opening files.(CVE-2017-16611) 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 id131512
    published2019-12-03
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/131512
    titleEulerOS Virtualization for ARM 64 3.0.3.0 : libXfont2 (EulerOS-SA-2019-2347)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-E27B435A7F.NASL
    descriptionSecurity fix for CVE-2017-16611 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
    modified2018-03-07
    plugin id107177
    published2018-03-07
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/107177
    titleFedora 27 : libXfont (2018-e27b435a7f)