Vulnerabilities > CVE-2018-3762 - Improper Preservation of Permissions vulnerability in Nextcloud Server

047910
CVSS 4.3 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
LOW
Integrity impact
NONE
Availability impact
NONE
network
low complexity
nextcloud
CWE-281
nessus

Summary

Nextcloud Server before 12.0.8 and 13.0.3 suffers from improper checks of dropped permissions for incoming shares allowing a user to still request previews for files it should not have access to.

Vulnerable Configurations

Part Description Count
Application
Nextcloud
429

Common Weakness Enumeration (CWE)

Nessus

  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2018-712.NASL
    descriptionThis update for nextcloud fixes the following issues : Security issues fixed : - CVE-2018-3761: Fix improper authentication on the OAuth2 token endpoint (bsc#1100344). - CVE-2018-3762: Fix improper checks of dropped permissions for incoming shares allowing a user to still request previews for files it should not have access to (bsc#1100343).
    last seen2020-06-05
    modified2018-07-12
    plugin id111037
    published2018-07-12
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/111037
    titleopenSUSE Security Update : nextcloud (openSUSE-2018-712)
    code
    #%NASL_MIN_LEVEL 80502
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from openSUSE Security Update openSUSE-2018-712.
    #
    # The text description of this plugin is (C) SUSE LLC.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(111037);
      script_version("1.3");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");
    
      script_cve_id("CVE-2018-3761", "CVE-2018-3762");
    
      script_name(english:"openSUSE Security Update : nextcloud (openSUSE-2018-712)");
      script_summary(english:"Check for the openSUSE-2018-712 patch");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote openSUSE host is missing a security update."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "This update for nextcloud fixes the following issues :
    
    Security issues fixed :
    
      - CVE-2018-3761: Fix improper authentication on the OAuth2
        token endpoint (bsc#1100344).
    
      - CVE-2018-3762: Fix improper checks of dropped
        permissions for incoming shares allowing a user to still
        request previews for files it should not have access to
        (bsc#1100343)."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1100343"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1100344"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Update the affected nextcloud package."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:N");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:nextcloud");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.0");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:42.3");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2018/07/11");
      script_set_attribute(attribute:"plugin_publication_date", value:"2018/07/12");
      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:"SuSE Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "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, "openSUSE");
    if (release !~ "^(SUSE15\.0|SUSE42\.3)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "15.0 / 42.3", release);
    if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    
    flag = 0;
    
    if ( rpm_check(release:"SUSE15.0", reference:"nextcloud-13.0.4-lp150.2.3.1") ) flag++;
    if ( rpm_check(release:"SUSE42.3", reference:"nextcloud-13.0.4-9.1") ) 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, "nextcloud");
    }
    
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2019-511.NASL
    descriptionThis update for nextcloud fixes the following issues : Security issues fixed : - CVE-2018-3761: Fix improper authentication on the OAuth2 token endpoint (bsc#1100344). - CVE-2018-3762: Fix improper checks of dropped permissions for incoming shares allowing a user to still request previews for files it should not have access to (bsc#1100343).
    last seen2020-05-31
    modified2019-03-27
    plugin id123216
    published2019-03-27
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/123216
    titleopenSUSE Security Update : nextcloud (openSUSE-2019-511)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from openSUSE Security Update openSUSE-2019-511.
    #
    # The text description of this plugin is (C) SUSE LLC.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(123216);
      script_version("1.3");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/26");
    
      script_cve_id("CVE-2018-3761", "CVE-2018-3762");
    
      script_name(english:"openSUSE Security Update : nextcloud (openSUSE-2019-511)");
      script_summary(english:"Check for the openSUSE-2019-511 patch");
    
      script_set_attribute(
        attribute:"synopsis",
        value:"The remote openSUSE host is missing a security update."
      );
      script_set_attribute(
        attribute:"description",
        value:
    "This update for nextcloud fixes the following issues :
    
    Security issues fixed :
    
      - CVE-2018-3761: Fix improper authentication on the OAuth2
        token endpoint (bsc#1100344).
    
      - CVE-2018-3762: Fix improper checks of dropped
        permissions for incoming shares allowing a user to still
        request previews for files it should not have access to
        (bsc#1100343)."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1100343"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1100344"
      );
      script_set_attribute(
        attribute:"solution",
        value:"Update the affected nextcloud package."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:N");
      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:R/S:U/C:H/I:H/A:N");
      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:opensuse:nextcloud");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.0");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2018/07/05");
      script_set_attribute(attribute:"patch_publication_date", value:"2019/03/23");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/03/27");
      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:"SuSE Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "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, "openSUSE");
    if (release !~ "^(SUSE15\.0)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "15.0", release);
    if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    
    flag = 0;
    
    if ( rpm_check(release:"SUSE15.0", reference:"nextcloud-13.0.4-lp150.2.3.1") ) 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, "nextcloud");
    }