Vulnerabilities > CVE-2019-15613 - Insufficient Verification of Data Authenticity vulnerability in multiple products

047910
CVSS 8.0 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
network
low complexity
nextcloud
opensuse
CWE-345
nessus

Summary

A bug in Nextcloud Server 17.0.1 causes the workflow rules to depend their behaviour on the file extension when checking file mimetypes.

Vulnerable Configurations

Part Description Count
Application
Nextcloud
588
OS
Opensuse
1

Common Attack Pattern Enumeration and Classification (CAPEC)

  • JSON Hijacking (aka JavaScript Hijacking)
    An attacker targets a system that uses JavaScript Object Notation (JSON) as a transport mechanism between the client and the server (common in Web 2.0 systems using AJAX) to steal possibly confidential information transmitted from the server back to the client inside the JSON object by taking advantage of the loophole in the browser's Same Origin Policy that does not prohibit JavaScript from one website to be included and executed in the context of another website. An attacker gets the victim to visit his or her malicious page that contains a script tag whose source points to the vulnerable system with a URL that requests a response from the server containing a JSON object with possibly confidential information. The malicious page also contains malicious code to capture the JSON object returned by the server before any other processing on it can take place, typically by overriding the JavaScript function used to create new objects. This hook allows the malicious code to get access to the creation of each object and transmit the possibly sensitive contents of the captured JSON object to the attackers' server. There is nothing in the browser's security model to prevent the attackers' malicious JavaScript code (originating from attacker's domain) to set up an environment (as described above) to intercept a JSON object response (coming from the vulnerable target system's domain), read its contents and transmit to the attackers' controlled site. The same origin policy protects the domain object model (DOM), but not the JSON.
  • Cache Poisoning
    An attacker exploits the functionality of cache technologies to cause specific data to be cached that aids the attackers' objectives. This describes any attack whereby an attacker places incorrect or harmful material in cache. The targeted cache can be an application's cache (e.g. a web browser cache) or a public cache (e.g. a DNS or ARP cache). Until the cache is refreshed, most applications or clients will treat the corrupted cache value as valid. This can lead to a wide range of exploits including redirecting web browsers towards sites that install malware and repeatedly incorrect calculations based on the incorrect value.
  • DNS Cache Poisoning
    A domain name server translates a domain name (such as www.example.com) into an IP address that Internet hosts use to contact Internet resources. An attacker modifies a public DNS cache to cause certain names to resolve to incorrect addresses that the attacker specifies. The result is that client applications that rely upon the targeted cache for domain name resolution will be directed not to the actual address of the specified domain name but to some other address. Attackers can use this to herd clients to sites that install malware on the victim's computer or to masquerade as part of a Pharming attack.
  • Cross-Site Scripting Using MIME Type Mismatch
    An attacker creates a file with scripting content but where the specified MIME type of the file is such that scripting is not expected. Some browsers will detect that the specified MIME type of the file does not match the actual type of the content and will automatically switch to using an interpreter for the real content type. If the browser does not invoke script filters before doing this, the attackers' script may run on the target unsanitized. For example, the MIME type text/plain may be used where the actual content is text/javascript or text/html. Since text does not contain scripting instructions, the stated MIME type would indicate that filtering is unnecessary. However, if the target application subsequently determines the file's real type and invokes the appropriate interpreter, scripted content could be invoked. In another example, img tags in HTML content could reference a renderable type file instead of an expected image file. The file extension and MIME type can describe an image file, but the file content can be text/javascript or text/html resulting in script execution. If the browser assumes all references in img tags are images, and therefore do not need to be filtered for scripts, this would bypass content filters. In a cross-site scripting attack, the attacker tricks the victim into accessing a URL that uploads a script file with an incorrectly specified MIME type. If the victim's browser switches to the appropriate interpreter without filtering, the attack will execute as a standard XSS attack, possibly revealing the victim's cookies or executing arbitrary script in their browser.
  • Spoofing of UDDI/ebXML Messages
    An attacker spoofs a UDDI, ebXML, or similar message in order to impersonate a service provider in an e-business transaction. UDDI, ebXML, and similar standards are used to identify businesses in e-business transactions. Among other things, they identify a particular participant, WSDL information for SOAP transactions, and supported communication protocols, including security protocols. By spoofing one of these messages an attacker could impersonate a legitimate business in a transaction or could manipulate the protocols used between a client and business. This could result in disclosure of sensitive information, loss of message integrity, or even financial fraud.

Nessus

NASL familySuSE Local Security Checks
NASL idOPENSUSE-2020-220.NASL
descriptionThis update for nextcloud fixes the following issues : Nextcloud was updated to 15.0.14 : - NC-SA-2020-002, CVE-2019-15613: workflow rules to depend their behaviour on the file extension when checking file mimetypes (boo#1162766) - NC-SA-2019-016, CVE-2019-15623: Exposure of Private Information caused the server to send it
last seen2020-03-18
modified2020-02-18
plugin id133757
published2020-02-18
reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/133757
titleopenSUSE Security Update : nextcloud (openSUSE-2020-220)
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from openSUSE Security Update openSUSE-2020-220.
#
# The text description of this plugin is (C) SUSE LLC.
#

include("compat.inc");

if (description)
{
  script_id(133757);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/02/20");

  script_cve_id("CVE-2019-15613", "CVE-2019-15621", "CVE-2019-15623", "CVE-2019-15624", "CVE-2020-8118", "CVE-2020-8119");

  script_name(english:"openSUSE Security Update : nextcloud (openSUSE-2020-220)");
  script_summary(english:"Check for the openSUSE-2020-220 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 :

Nextcloud was updated to 15.0.14 :

  - NC-SA-2020-002, CVE-2019-15613: workflow rules to depend
    their behaviour on the file extension when checking file
    mimetypes (boo#1162766)

  - NC-SA-2019-016, CVE-2019-15623: Exposure of Private
    Information caused the server to send it's domain and
    user IDs to the Nextcloud Lookup Server without any
    further data when the Lookup server is disabled
    (boo#1162775)

  - NC-SA-2019-015, CVE-2019-15624: Improper Input
    Validation allowed group admins to create users with IDs
    of system folders (boo#1162776)

  - NC-SA-2019-012, CVE-2020-8119: Improper authorization
    caused leaking of previews and files when a file-drop
    share link is opened via the gallery app (boo#1162781)

  - NC-SA-2019-014, CVE-2020-8118: An authenticated
    server-side request forgery allowed to detect local and
    remote services when adding a new subscription in the
    calendar application (boo#1162782)

  - NC-SA-2020-012, CVE-2019-15621: Improper permissions
    preservation causes sharees to be able to reshare with
    write permissions when sharing the mount point of a
    share they received, as a public link (boo#1162784)

  - To many changes. For detail see:
    https://nextcloud.com/changelog/

nextcloud was updated to 13.0.12 :

  - Fix NC-SA-2020-001

  - To many changes. For detail see:
    https://nextcloud.com/changelog/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1162766"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1162775"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1162776"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1162781"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1162782"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1162784"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://nextcloud.com/changelog/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected nextcloud package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:S/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:L/UI:R/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:opensuse:nextcloud");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.1");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/02/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/02/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/02/18");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 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\.1)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "15.1", release);
if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);



flag = 0;

if ( rpm_check(release:"SUSE15.1", reference:"nextcloud-15.0.14-lp151.2.3.1") ) 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");
}