Vulnerabilities > CVE-2018-12474 - Improper Input Validation vulnerability in Opensuse TAR SCM

047910
CVSS 9.8 - CRITICAL
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
network
low complexity
opensuse
CWE-20
critical
nessus

Summary

Improper input validation in obs-service-tar_scm of Open Build Service allows remote attackers to cause access and extract information outside the current build or cause the creation of file in attacker controlled locations. Affected releases are openSUSE Open Build Service: versions prior to 51a17c553b6ae2598820b7a90fd0c11502a49106.

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.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

NASL familySuSE Local Security Checks
NASL idOPENSUSE-2019-326.NASL
descriptionThis update for obs-service-tar_scm fixes the following issues : Security vulnerabilities addressed : - CVE-2018-12473: Fixed a path traversal issue, which allowed users to access files outside of the repository using relative paths (bsc#1105361) - CVE-2018-12474: Fixed an issue whereby crafted service parameters allowed for unexpected behaviour (bsc#1107507) - CVE-2018-12476: Fixed an issue whereby the outfilename parameter allowed to write files outside of package directory (bsc#1107944) Other bug fixes and changes made : - Prefer UTF-8 locale as output format for changes - added KankuFile - fix problems with unicode source files - added python-six to Requires in specfile - better encoding handling - fixes bsc#1082696 and bsc#1076410 - fix unicode in containers - move to python3 - added logging for better debugging changesgenerate - raise exception if no changesauthor given - Stop using @opensuse.org addresses to indicate a missing address - move argparse dep to -common package - allow submodule and ssl options in appimage - sync spec file as used in openSUSE:Tools project - check encoding problems for svn and print proper error msg - added new param
last seen2020-06-01
modified2020-06-02
plugin id122848
published2019-03-14
reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/122848
titleopenSUSE Security Update : obs-service-tar_scm (openSUSE-2019-326)
code
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from openSUSE Security Update openSUSE-2019-326.
#
# The text description of this plugin is (C) SUSE LLC.
#

include("compat.inc");

if (description)
{
  script_id(122848);
  script_version("1.2");
  script_cvs_date("Date: 2020/02/05");

  script_cve_id("CVE-2018-12473", "CVE-2018-12474", "CVE-2018-12476");

  script_name(english:"openSUSE Security Update : obs-service-tar_scm (openSUSE-2019-326)");
  script_summary(english:"Check for the openSUSE-2019-326 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 obs-service-tar_scm fixes the following issues :

Security vulnerabilities addressed :

  - CVE-2018-12473: Fixed a path traversal issue, which
    allowed users to access files outside of the repository
    using relative paths (bsc#1105361)

  - CVE-2018-12474: Fixed an issue whereby crafted service
    parameters allowed for unexpected behaviour
    (bsc#1107507)

  - CVE-2018-12476: Fixed an issue whereby the outfilename
    parameter allowed to write files outside of package
    directory (bsc#1107944)

Other bug fixes and changes made :

  - Prefer UTF-8 locale as output format for changes

  - added KankuFile

  - fix problems with unicode source files

  - added python-six to Requires in specfile

  - better encoding handling

  - fixes bsc#1082696 and bsc#1076410

  - fix unicode in containers

  - move to python3

  - added logging for better debugging changesgenerate

  - raise exception if no changesauthor given

  - Stop using @opensuse.org addresses to indicate a missing
    address

  - move argparse dep to -common package

  - allow submodule and ssl options in appimage

  - sync spec file as used in openSUSE:Tools project

  - check encoding problems for svn and print proper error
    msg

  - added new param '--locale'

  - separate service file installation in GNUmakefile

  - added glibc as Recommends in spec file

  - cleanup for broken svn caches

  - another fix for unicode problem in obs_scm

  - Final fix for unicode in filenames

  - Another attempt to fix unicode filenames in
    prep_tree_for_archive

  - Another attempt to fix unicode filenames in
    prep_tree_for_archive

  - fix bug with unicode filenames in prep_tree_for_archive

  - reuse _service*_servicedata/changes files from previous
    service runs

  - fix problems with unicode characters in commit messages
    for changeloggenerate

  - fix encoding issues if commit message contains utf8 char

  - revert encoding for old changes file

  - remove hardcoded utf-8 encodings

  - Add support for extract globbing

  - split pylint2 in GNUmakefile

  - fix check for '--reproducible'

  - create reproducible obscpio archives

  - fix regression from 44b3bee

  - Support also SSH urls for Git

  - check name/version option in obsinfo for slashes

  - check url for remote url

  - check symlinks in subdir parameter

  - check filename for slashes

  - disable follow_symlinks in extract feature

  - switch to obs_scm for this package

  - run download_files in appimage and snapcraft case

  - check --extract file path for parent dir

  - Fix parameter descriptions

  - changed os.removedirs -> shutil.rmtree

  - Adding information regarding the *package-metadata*
    option for the *tar* service The tar service is highly
    useful in combination with the *obscpio* service. After
    the fix for the metadata for the latter one, it is
    important to inform the users of the *tar* service that
    metadata is kept only if the flag *package-metadata* is
    enabled. Add the flag to the .service file for
    mentioning that.

  - Allow metadata packing for CPIO archives when desired As
    of now, metadata are always excluded from *obscpio*
    packages. This is because the *package-metadata* flag is
    ignored; this change (should) make *obscpio* aware of
    it.

  - improve handling of corrupt git cache directories

  - only do git stash save/pop if we have a non-empty
    working tree (#228)

  - don't allow DEBUG_TAR_SCM to change behaviour (#240)

  - add stub user docs in lieu of something proper (#238)

  - Remove clone_dir if clone fails

  - python-unittest2 is only required for the optional make
    check

  - move python-unittest2 dep to test suite only part
    (submission by olh)

  - Removing redundant pass statement

  - missing import for logging functions.

  - [backend] Adding http proxy support

  - python-unittest2 is only required for the optional make
    check

  - make installation of scm's optional

  - add a lot more detail to README

  - Git clone with --no-checkout in prepare_working_copy

  - Refactor and simplify git prepare_working_copy

  - Only use current dir if it actually looks like git
    (Fixes #202)

  - reactivate test_obscpio_extract_d

  - fix broken test create_archive

  - fix broken tests for broken-links

  - changed PREFIX in Gnumakefile to /usr

  - new cli option --skip-cleanup

  - fix for broken links

  - fix reference to snapcraft YAML file

  - fix docstring typo in TarSCM.scm.tar.fetch_upstream

  - acknowledge deficiencies in dev docs

  - wrap long lines in README

This update was imported from the SUSE:SLE-15:Update update project."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1076410"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1082696"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1105361"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1107507"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1107944"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected obs-service-tar_scm 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:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:obs-service-appimage");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:obs-service-obs_scm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:obs-service-obs_scm-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:obs-service-snapcraft");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:obs-service-tar");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:obs-service-tar_scm");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.0");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/10/02");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/03/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/03/14");
  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:"obs-service-appimage-0.10.5.1551309990.79898c7-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"obs-service-obs_scm-0.10.5.1551309990.79898c7-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"obs-service-obs_scm-common-0.10.5.1551309990.79898c7-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"obs-service-snapcraft-0.10.5.1551309990.79898c7-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"obs-service-tar-0.10.5.1551309990.79898c7-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"obs-service-tar_scm-0.10.5.1551309990.79898c7-lp150.2.3.1") ) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
  else security_hole(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "obs-service-appimage / obs-service-obs_scm / etc");
}