Vulnerabilities > CVE-2018-12434 - Information Exposure vulnerability in Openbsd Libressl

047910
CVSS 1.9 - LOW
Attack vector
LOCAL
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
NONE
Availability impact
NONE
local
openbsd
CWE-200
nessus
NVD
Published: 2018-06-15
Updated: 2018-08-06

Summary

LibreSSL before 2.6.5 and 2.7.x before 2.7.4 allows a memory-cache side-channel attack on DSA and ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover a key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.

Vulnerable Configurations

Part Description Count
Application
Openbsd
60

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Subverting Environment Variable Values
    The attacker directly or indirectly modifies environment variables used by or controlling the target software. The attacker's goal is to cause the target software to deviate from its expected operation in a manner that benefits the attacker.
  • Footprinting
    An attacker engages in probing and exploration activity to identify constituents and properties of the target. Footprinting is a general term to describe a variety of information gathering techniques, often used by attackers in preparation for some attack. It consists of using tools to learn as much as possible about the composition, configuration, and security mechanisms of the targeted application, system or network. Information that might be collected during a footprinting effort could include open ports, applications and their versions, network topology, and similar information. While footprinting is not intended to be damaging (although certain activities, such as network scans, can sometimes cause disruptions to vulnerable applications inadvertently) it may often pave the way for more damaging attacks.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Browser Fingerprinting
    An attacker carefully crafts small snippets of Java Script to efficiently detect the type of browser the potential victim is using. Many web-based attacks need prior knowledge of the web browser including the version of browser to ensure successful exploitation of a vulnerability. Having this knowledge allows an attacker to target the victim with attacks that specifically exploit known or zero day weaknesses in the type and version of the browser used by the victim. Automating this process via Java Script as a part of the same delivery system used to exploit the browser is considered more efficient as the attacker can supply a browser fingerprinting method and integrate it with exploit code, all contained in Java Script and in response to the same web page request by the browser.
  • Session Credential Falsification through Prediction
    This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking.

Nessus

  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2018-953.NASL
    descriptionThis update for libressl to version 2.8.0 fixes the following issues : Security issues fixed : - CVE-2018-12434: Avoid a timing side-channel leak when generating DSA and ECDSA signatures. (boo#1097779) - Reject excessively large primes in DH key generation. - CVE-2018-8970: Fixed a bug in int_x509_param_set_hosts, calling strlen() if name length provided is 0 to match the OpenSSL behaviour. (boo#1086778) - Fixed an out-of-bounds read and crash in DES-fcrypt (boo#1065363) You can find a detailed list of changes [here](https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.8.0-rel notes.txt).
    last seen2020-06-05
    modified2018-09-04
    plugin id112267
    published2018-09-04
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/112267
    titleopenSUSE Security Update : libressl (openSUSE-2018-953)
    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-2018-953.
#
# The text description of this plugin is (C) SUSE LLC.
#

include("compat.inc");

if (description)
{
  script_id(112267);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");

  script_cve_id("CVE-2018-12434", "CVE-2018-8970");

  script_name(english:"openSUSE Security Update : libressl (openSUSE-2018-953)");
  script_summary(english:"Check for the openSUSE-2018-953 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 libressl to version 2.8.0 fixes the following issues :

Security issues fixed :

  - CVE-2018-12434: Avoid a timing side-channel leak when
    generating DSA and ECDSA signatures. (boo#1097779)

  - Reject excessively large primes in DH key generation.

  - CVE-2018-8970: Fixed a bug in int_x509_param_set_hosts,
    calling strlen() if name length provided is 0 to match
    the OpenSSL behaviour. (boo#1086778)

  - Fixed an out-of-bounds read and crash in DES-fcrypt
    (boo#1065363)

You can find a detailed list of changes
[here](https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.8.0-rel
notes.txt)."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1065363"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1086778"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1097779"
  );
  # https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.8.0-relnotes.txt
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?5af67e40"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected libressl packages."
  );
  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:H/PR:N/UI:N/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:libcrypto43");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libcrypto43-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libcrypto43-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libcrypto43-debuginfo-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl-debugsource");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl-devel-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libssl45");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libssl45-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libssl45-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libssl45-debuginfo-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libtls17");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libtls17-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libtls17-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libtls17-debuginfo-32bit");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:42.3");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/09/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/09/04");
  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", "Host/cpu");

  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 !~ "^(SUSE42\.3)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "42.3", release);
if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

ourarch = get_kb_item("Host/cpu");
if (!ourarch) audit(AUDIT_UNKNOWN_ARCH);
if (ourarch !~ "^(i586|i686|x86_64)$") audit(AUDIT_ARCH_NOT, "i586 / i686 / x86_64", ourarch);

flag = 0;

if ( rpm_check(release:"SUSE42.3", reference:"libcrypto43-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", reference:"libcrypto43-debuginfo-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", reference:"libressl-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", reference:"libressl-debuginfo-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", reference:"libressl-debugsource-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", reference:"libressl-devel-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", reference:"libssl45-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", reference:"libssl45-debuginfo-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", reference:"libtls17-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", reference:"libtls17-debuginfo-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", cpu:"x86_64", reference:"libcrypto43-32bit-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", cpu:"x86_64", reference:"libcrypto43-debuginfo-32bit-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", cpu:"x86_64", reference:"libressl-devel-32bit-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", cpu:"x86_64", reference:"libssl45-32bit-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", cpu:"x86_64", reference:"libssl45-debuginfo-32bit-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", cpu:"x86_64", reference:"libtls17-32bit-2.8.0-11.1") ) flag++;
if ( rpm_check(release:"SUSE42.3", cpu:"x86_64", reference:"libtls17-debuginfo-32bit-2.8.0-11.1") ) 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, "libcrypto43 / libcrypto43-32bit / libcrypto43-debuginfo / etc");
}
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2019-644.NASL
    descriptionThis update for libressl to version 2.8.0 fixes the following issues : Security issues fixed : - CVE-2018-12434: Avoid a timing side-channel leak when generating DSA and ECDSA signatures. (boo#1097779) - Reject excessively large primes in DH key generation. Other bugs fixed : - Fixed a pair of 20+ year-old bugs in X509_NAME_add_entry. - Tighten up checks for various X509_VERIFY_PARAM functions,
    last seen2020-06-01
    modified2020-06-02
    plugin id123282
    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/123282
    titleopenSUSE Security Update : libressl (openSUSE-2019-644)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from openSUSE Security Update openSUSE-2019-644.
#
# The text description of this plugin is (C) SUSE LLC.
#

include("compat.inc");

if (description)
{
  script_id(123282);
  script_version("1.2");
  script_cvs_date("Date: 2020/01/30");

  script_cve_id("CVE-2018-12434");

  script_name(english:"openSUSE Security Update : libressl (openSUSE-2019-644)");
  script_summary(english:"Check for the openSUSE-2019-644 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 libressl to version 2.8.0 fixes the following issues :

Security issues fixed :

  - CVE-2018-12434: Avoid a timing side-channel leak when
    generating DSA and ECDSA signatures. (boo#1097779)

  - Reject excessively large primes in DH key generation.

Other bugs fixed :

  - Fixed a pair of 20+ year-old bugs in
    X509_NAME_add_entry.

  - Tighten up checks for various X509_VERIFY_PARAM
    functions, 'poisoning' parameters so that an unverified
    certificate cannot be used if it fails verification.

  - Fixed a potential memory leak on failure in
    ASN1_item_digest.

  - Fixed a potential memory alignment crash in
    asn1_item_combine_free.

  - Removed unused SSL3_FLAGS_DELAY_CLIENT_FINISHED and
    SSL3_FLAGS_POP_BUFFER flags in write path, simplifying
    IO paths.

  - Removed SSL_OP_TLS_ROLLBACK_BUG buggy client
    workarounds.

  - Added const annotations to many existing APIs from
    OpenSSL, making interoperability easier for downstream
    applications.

  - Added a missing bounds check in c2i_ASN1_BIT_STRING.

  - Removed three remaining single DES cipher suites.

  - Fixed a potential leak/incorrect return value in DSA
    signature generation.

  - Added a blinding value when generating DSA and ECDSA
    signatures, in order to reduce the possibility of a
    side-channel attack leaking the private key.

  - Added ECC constant time scalar multiplication support.

  - Revised the implementation of RSASSA-PKCS1-v1_5 to match
    the specification in RFC 8017."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1097779"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected libressl packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:P/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/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:libcrypto43");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libcrypto43-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libcrypto43-32bit-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libcrypto43-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl-debugsource");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libressl-devel-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libssl45");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libssl45-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libssl45-32bit-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libssl45-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libtls17");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libtls17-32bit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libtls17-32bit-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:libtls17-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.0");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/06/15");
  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", "Host/cpu");

  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);

ourarch = get_kb_item("Host/cpu");
if (!ourarch) audit(AUDIT_UNKNOWN_ARCH);
if (ourarch !~ "^(i586|i686|x86_64)$") audit(AUDIT_ARCH_NOT, "i586 / i686 / x86_64", ourarch);

flag = 0;

if ( rpm_check(release:"SUSE15.0", reference:"libcrypto43-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"libcrypto43-debuginfo-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"libressl-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"libressl-debuginfo-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"libressl-debugsource-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"libressl-devel-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"libssl45-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"libssl45-debuginfo-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"libtls17-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"libtls17-debuginfo-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", cpu:"x86_64", reference:"libcrypto43-32bit-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", cpu:"x86_64", reference:"libcrypto43-32bit-debuginfo-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", cpu:"x86_64", reference:"libressl-devel-32bit-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", cpu:"x86_64", reference:"libssl45-32bit-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", cpu:"x86_64", reference:"libssl45-32bit-debuginfo-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", cpu:"x86_64", reference:"libtls17-32bit-2.8.0-lp150.2.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", cpu:"x86_64", reference:"libtls17-32bit-debuginfo-2.8.0-lp150.2.3.1") ) flag++;

if (flag)
{
  if (report_verbosity > 0) security_note(port:0, extra:rpm_report_get());
  else security_note(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "libcrypto43 / libcrypto43-32bit / libcrypto43-32bit-debuginfo / etc");
}
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2018-950.NASL
    descriptionThis update for libressl to version 2.8.0 fixes the following issues : Security issues fixed : - CVE-2018-12434: Avoid a timing side-channel leak when generating DSA and ECDSA signatures. (boo#1097779) - Reject excessively large primes in DH key generation. Other bugs fixed : - Fixed a pair of 20+ year-old bugs in X509_NAME_add_entry. - Tighten up checks for various X509_VERIFY_PARAM functions,
    last seen2020-06-05
    modified2018-09-04
    plugin id112264
    published2018-09-04
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/112264
    titleopenSUSE Security Update : libressl (openSUSE-2018-950)

References