Vulnerabilities > CVE-2013-2061 - Information Exposure vulnerability in multiple products

047910
CVSS 2.6 - LOW
Attack vector
NETWORK
Attack complexity
HIGH
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
NONE
Availability impact
NONE
network
high complexity
openvpn
opensuse
CWE-200
nessus

Summary

The openvpn_decrypt function in crypto.c in OpenVPN 2.3.0 and earlier, when running in UDP mode, allows remote attackers to obtain sensitive information via a timing attack involving an HMAC comparison function that does not run in constant time and a padding oracle attack on the CBC mode cipher.

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 familyFedora Local Security Checks
    NASL idFEDORA_2013-7531.NASL
    descriptionFix for SSL vulnerability. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-03-17
    modified2013-05-16
    plugin id66452
    published2013-05-16
    reporterThis script is Copyright (C) 2013-2020 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/66452
    titleFedora 18 : openvpn-2.3.1-2.fc18 (2013-7531)
    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 2013-7531.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(66452);
      script_version("1.8");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/12");
    
      script_cve_id("CVE-2013-2061");
      script_bugtraq_id(59672);
      script_xref(name:"FEDORA", value:"2013-7531");
    
      script_name(english:"Fedora 18 : openvpn-2.3.1-2.fc18 (2013-7531)");
      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:
    "Fix for SSL vulnerability.
    
    Note that Tenable Network Security has extracted the preceding
    description block directly from the Fedora security advisory. 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://bugzilla.redhat.com/show_bug.cgi?id=960196"
      );
      # https://lists.fedoraproject.org/pipermail/package-announce/2013-May/105609.html
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?b58ca906"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Update the affected openvpn package."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:P/I:N/A:N");
      script_set_cvss_temporal_vector("CVSS2#E:ND/RL:OF/RC:C");
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"false");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:openvpn");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:18");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2013/05/07");
      script_set_attribute(attribute:"plugin_publication_date", value:"2013/05/16");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2013-2020 Tenable Network Security, Inc.");
      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 = eregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
    if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
    os_ver = os_ver[1];
    if (! ereg(pattern:"^18([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 18.x", "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:"FC18", reference:"openvpn-2.3.1-2.fc18")) 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, "openvpn");
    }
    
  • NASL familySuSE Local Security Checks
    NASL idSUSE_11_OPENVPN-131101.NASL
    descriptionOpenVPN used a non-constant-time memcmp in HMAC comparison in openvpn_decrypt that might have allowed remote attackers to gain knowledge of plaintext data. (CVE-2013-2061)
    last seen2020-06-05
    modified2013-11-29
    plugin id71137
    published2013-11-29
    reporterThis script is Copyright (C) 2013-2020 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/71137
    titleSuSE 11.3 Security Update : openvpn (SAT Patch Number 8493)
    code
    #%NASL_MIN_LEVEL 80502
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from SuSE 11 update information. The text itself is
    # copyright (C) Novell, Inc.
    #
    
    if (NASL_LEVEL < 3000) exit(0);
    
    include("compat.inc");
    
    if (description)
    {
      script_id(71137);
      script_version("1.2");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");
    
      script_cve_id("CVE-2013-2061");
    
      script_name(english:"SuSE 11.3 Security Update : openvpn (SAT Patch Number 8493)");
      script_summary(english:"Checks rpm output for the updated packages");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote SuSE 11 host is missing one or more security updates."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "OpenVPN used a non-constant-time memcmp in HMAC comparison in
    openvpn_decrypt that might have allowed remote attackers to gain
    knowledge of plaintext data. (CVE-2013-2061)"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.novell.com/show_bug.cgi?id=843509"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"http://support.novell.com/security/cve/CVE-2013-2061.html"
      );
      script_set_attribute(attribute:"solution", value:"Apply SAT patch number 8493.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:P/I:N/A:N");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:11:openvpn");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:11:openvpn-auth-pam-plugin");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:suse_linux:11");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2013/11/01");
      script_set_attribute(attribute:"plugin_publication_date", value:"2013/11/29");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2013-2020 Tenable Network Security, Inc.");
      script_family(english:"SuSE Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/cpu", "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)11") audit(AUDIT_OS_NOT, "SuSE 11");
    if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    cpu = get_kb_item("Host/cpu");
    if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
    if (cpu !~ "^i[3-6]86$" && "x86_64" >!< cpu && "s390x" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "SuSE 11", cpu);
    
    pl = get_kb_item("Host/SuSE/patchlevel");
    if (isnull(pl) || int(pl) != 3) audit(AUDIT_OS_NOT, "SuSE 11.3");
    
    
    flag = 0;
    if (rpm_check(release:"SLED11", sp:3, cpu:"i586", reference:"openvpn-2.0.9-143.40.5")) flag++;
    if (rpm_check(release:"SLED11", sp:3, cpu:"x86_64", reference:"openvpn-2.0.9-143.40.5")) flag++;
    if (rpm_check(release:"SLES11", sp:3, reference:"openvpn-2.0.9-143.40.5")) flag++;
    if (rpm_check(release:"SLES11", sp:3, reference:"openvpn-auth-pam-plugin-2.0.9-143.40.5")) flag++;
    
    
    if (flag)
    {
      if (report_verbosity > 0) security_note(port:0, extra:rpm_report_get());
      else security_note(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");
    
  • NASL familyGentoo Local Security Checks
    NASL idGENTOO_GLSA-201311-13.NASL
    descriptionThe remote host is affected by the vulnerability described in GLSA-201311-13 (OpenVPN: Multiple vulnerabilities) Multiple vulnerabilities have been discovered in OpenVPN. Please review the CVE identifiers referenced below for details. Impact : A remote attacker may be able to recover plaintext from an encrypted communication. Another vulnerability could allow remote attacker perform a Man-in-the-Middle attack. Workaround : There is no known workaround at this time.
    last seen2020-06-01
    modified2020-06-02
    plugin id70997
    published2013-11-21
    reporterThis script is Copyright (C) 2013-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/70997
    titleGLSA-201311-13 : OpenVPN: Multiple vulnerabilities
  • NASL familyAmazon Linux Local Security Checks
    NASL idALA_ALAS-2013-201.NASL
    descriptionThe openvpn_decrypt function in crypto.c in OpenVPN 2.3.0 and earlier, when running in UDP mode, allows remote attackers to obtain sensitive information via a timing attack involving an HMAC comparison function that does not run in constant time and a padding oracle attack on the CBC mode cipher.
    last seen2020-06-01
    modified2020-06-02
    plugin id69759
    published2013-09-04
    reporterThis script is Copyright (C) 2013-2018 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/69759
    titleAmazon Linux AMI : openvpn (ALAS-2013-201)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2013-7552.NASL
    descriptionFix for SSL vulnerability. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-03-17
    modified2013-05-16
    plugin id66453
    published2013-05-16
    reporterThis script is Copyright (C) 2013-2020 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/66453
    titleFedora 17 : openvpn-2.3.1-2.fc17 (2013-7552)
  • NASL familyWindows
    NASL idOPENVPN_2_3_1.NASL
    descriptionAccording to its self-reported version number, the version of OpenVPN installed on the remote Windows host is prior to 2.3.1. It is, therefore, affected by an information disclosure vulnerability in the crypto.c component due to its HMAC comparison function not running in constant time. An unauthenticated, remote attacker can exploit this, via a timing attack, to disclose potentially sensitive information.
    last seen2020-06-01
    modified2020-06-02
    plugin id125260
    published2019-05-17
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/125260
    titleOpenVPN < 2.3.1 Information Disclosure Vulnerability (Windows)
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-2368-1.NASL
    descriptionIt was discovered that OpenVPN incorrectly handled HMAC comparisons when running in UDP mode. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could possibly be used to perform a plaintext recovery attack. 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 id78041
    published2014-10-03
    reporterUbuntu Security Notice (C) 2014-2019 Canonical, Inc. / NASL script (C) 2014-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/78041
    titleUbuntu 12.04 LTS : openvpn vulnerability (USN-2368-1)
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2013-823.NASL
    descriptionThe following security issues were fixed : - Applied upstream patch changing to use a constant time memcmp when comparing HMACs in openvpn_decrypt to address ciphertext injection in UDP mode (CVE-2013-2061, bnc#843509). [0006-openvpn-2.0.9-HMAC-memcmp-CVE-2013-2061_bnc843509. patch] Changes in openvpn : - Applied upstream patch changing to use a constant time memcmp when comparing HMACs in openvpn_decrypt to address ciphertext injection in UDP mode (CVE-2013-2061, bnc#843509). [0006-openvpn-2.0.9-HMAC-memcmp-CVE-2013-2061_bnc843509. patch]
    last seen2020-06-05
    modified2014-06-13
    plugin id75191
    published2014-06-13
    reporterThis script is Copyright (C) 2014-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/75191
    titleopenSUSE Security Update : openvpn (openSUSE-SU-2013:1645-1)
  • NASL familySuSE Local Security Checks
    NASL idSUSE_11_OPENVPN-131031.NASL
    descriptionOpenVPN used a non-constant-time memcmp in HMAC comparison in openvpn_decrypt that might have allowed remote attackers to gain knowledge of plaintext data. (CVE-2013-2061)
    last seen2020-06-05
    modified2013-11-29
    plugin id71136
    published2013-11-29
    reporterThis script is Copyright (C) 2013-2020 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/71136
    titleSuSE 11.2 Security Update : openvpn (SAT Patch Number 8496)
  • NASL familyMandriva Local Security Checks
    NASL idMANDRIVA_MDVSA-2013-167.NASL
    descriptionUpdated openvpn package fixes security vulnerability : OpenVPN 2.3.0 and earlier running in UDP mode are subject to chosen ciphertext injection due to a non-constant-time HMAC comparison function. Plaintext recovery may be possible using a padding oracle attack on the CBC mode cipher implementation of the crypto library, optimistically at a rate of about one character per 3 hours. PolarSSL seems vulnerable to such an attack; the vulnerability of OpenSSL has not been verified or tested (CVE-2013-2061).
    last seen2020-06-01
    modified2020-06-02
    plugin id66614
    published2013-05-28
    reporterThis script is Copyright (C) 2013-2019 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/66614
    titleMandriva Linux Security Advisory : openvpn (MDVSA-2013:167)
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_92F30415993511E2AD4C080027EF73EC.NASL
    descriptionThe OpenVPN project reports : OpenVPN 2.3.0 and earlier running in UDP mode are subject to chosen ciphertext injection due to a non-constant-time HMAC comparison function.
    last seen2020-06-01
    modified2020-06-02
    plugin id65846
    published2013-04-08
    reporterThis script is Copyright (C) 2013-2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/65846
    titleFreeBSD : OpenVPN -- potential side-channel/timing attack when comparing HMACs (92f30415-9935-11e2-ad4c-080027ef73ec)