Vulnerabilities > CVE-2020-12244 - Improper Verification of Cryptographic Signature vulnerability in multiple products

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
NONE
Availability impact
NONE

Summary

An issue has been found in PowerDNS Recursor 4.1.0 through 4.3.0 where records in the answer section of a NXDOMAIN response lacking an SOA were not properly validated in SyncRes::processAnswer, allowing an attacker to bypass DNSSEC validation.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Padding Oracle Crypto Attack
    An attacker is able to efficiently decrypt data without knowing the decryption key if a target system leaks data on whether or not a padding error happened while decrypting the ciphertext. A target system that leaks this type of information becomes the padding oracle and an attacker is able to make use of that oracle to efficiently decrypt data without knowing the decryption key by issuing on average 128*b calls to the padding oracle (where b is the number of bytes in the ciphertext block). In addition to performing decryption, an attacker is also able to produce valid ciphertexts (i.e., perform encryption) by using the padding oracle, all without knowing the encryption key. Any cryptosystem can be vulnerable to padding oracle attacks if the encrypted messages are not authenticated to ensure their validity prior to decryption, and then the information about padding error is leaked to the attacker. This attack technique may be used, for instance, to break CAPTCHA systems or decrypt/modify state information stored in client side objects (e.g., hidden fields or cookies). This attack technique is a side-channel attack on the cryptosystem that uses a data leak from an improperly implemented decryption routine to completely subvert the cryptosystem. The one bit of information that tells the attacker whether a padding error during decryption has occurred, in whatever form it comes, is sufficient for the attacker to break the cryptosystem. That bit of information can come in a form of an explicit error message about a padding error, a returned blank page, or even the server taking longer to respond (a timing attack). This attack can be launched cross domain where an attacker is able to use cross-domain information leaks to get the bits of information from the padding oracle from a target system / service with which the victim is communicating. To do so an attacker sends a request containing ciphertext to the target system. Due to the browser's same origin policy, the attacker is not able to see the response directly, but can use cross-domain information leak techniques to still get the information needed (i.e., information on whether or not a padding error has occurred). For instance, this can be done using "img" tag plus the onerror()/onload() events. The attacker's JavaScript can make web browsers to load an image on the target site, and know if the image is loaded or not. This is 1-bit information needed for the padding oracle attack to work: if the image is loaded, then it is valid padding, otherwise it is not.

Nessus

  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2020-698.NASL
    descriptionThis update for pdns-recursor fixes the following issues : - update to 4.1.16 - fixes an issue where records in the answer section of a NXDOMAIN response lacking an SOA were not properly validated (CVE-2020-12244, boo#1171553) - fixes an issue where invalid hostname on the server can result in disclosure of invalid memory (CVE-2020-10030, boo#1171553) - fixes an issue in the DNS protocol has been found that allows malicious parties to use recursive DNS services to attack third party authoritative name servers (CVE-2020-10995, boo#1171553) For details see https://doc.powerdns.com/recursor/changelog/4.1.html#change-4.1.16
    last seen2020-05-31
    modified2020-05-26
    plugin id136885
    published2020-05-26
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136885
    titleopenSUSE Security Update : pdns-recursor (openSUSE-2020-698)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from openSUSE Security Update openSUSE-2020-698.
    #
    # The text description of this plugin is (C) SUSE LLC.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136885);
      script_version("1.2");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/28");
    
      script_cve_id("CVE-2020-10030", "CVE-2020-10995", "CVE-2020-12244");
    
      script_name(english:"openSUSE Security Update : pdns-recursor (openSUSE-2020-698)");
      script_summary(english:"Check for the openSUSE-2020-698 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 pdns-recursor fixes the following issues :
    
      - update to 4.1.16
    
      - fixes an issue where records in the answer section of a
        NXDOMAIN response lacking an SOA were not properly
        validated (CVE-2020-12244, boo#1171553)
    
      - fixes an issue where invalid hostname on the server can
        result in disclosure of invalid memory (CVE-2020-10030,
        boo#1171553)
    
      - fixes an issue in the DNS protocol has been found that
        allows malicious parties to use recursive DNS services
        to attack third party authoritative name servers
        (CVE-2020-10995, boo#1171553)
    
    For details see
    https://doc.powerdns.com/recursor/changelog/4.1.html#change-4.1.16"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1171553"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://doc.powerdns.com/recursor/changelog/4.1.html#change-4.1.16"
      );
      script_set_attribute(
        attribute:"solution",
        value:"Update the affected pdns-recursor packages."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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: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:pdns-recursor");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:pdns-recursor-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:pdns-recursor-debugsource");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.1");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/19");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/23");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/26");
      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", "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\.1)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "15.1", 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 !~ "^(x86_64)$") audit(AUDIT_ARCH_NOT, "x86_64", ourarch);
    
    flag = 0;
    
    if ( rpm_check(release:"SUSE15.1", reference:"pdns-recursor-4.1.12-lp151.3.3.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"pdns-recursor-debuginfo-4.1.12-lp151.3.3.1") ) flag++;
    if ( rpm_check(release:"SUSE15.1", reference:"pdns-recursor-debugsource-4.1.12-lp151.3.3.1") ) 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, "pdns-recursor / pdns-recursor-debuginfo / pdns-recursor-debugsource");
    }
    
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_F9C5A4109B4E11EAAC3F6805CA2FA271.NASL
    descriptionPowerDNS Team reports : CVE-2020-10995: An issue in the DNS protocol has been found that allow malicious parties to use recursive DNS services to attack third party authoritative name servers. The attack uses a crafted reply by an authoritative name server to amplify the resulting traffic between the recursive and other authoritative name servers. Both types of service can suffer degraded performance as an effect. CVE-2020-12244: An issue has been found in PowerDNS Recursor 4.1.0 through 4.3.0 where records in the answer section of a NXDOMAIN response lacking an SOA were not properly validated in SyncRes::processAnswer. This would allow an attacker in position of man-in-the-middle to send a NXDOMAIN answer for a name that does exist, bypassing DNSSEC validation. CVE-2020-10030: An issue has been found in PowerDNS Authoritative Server allowing an attacker with enough privileges to change the system
    last seen2020-06-06
    modified2020-05-28
    plugin id136942
    published2020-05-28
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136942
    titleFreeBSD : powerdns-recursor -- multiple vulnerabilities (f9c5a410-9b4e-11ea-ac3f-6805ca2fa271)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from the FreeBSD VuXML database :
    #
    # Copyright 2003-2020 Jacques Vidrine and contributors
    #
    # Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
    # HTML, PDF, PostScript, RTF and so forth) with or without modification,
    # are permitted provided that the following conditions are met:
    # 1. Redistributions of source code (VuXML) must retain the above
    #    copyright notice, this list of conditions and the following
    #    disclaimer as the first lines of this file unmodified.
    # 2. Redistributions in compiled form (transformed to other DTDs,
    #    published online in any format, converted to PDF, PostScript,
    #    RTF and other formats) must reproduce the above copyright
    #    notice, this list of conditions and the following disclaimer
    #    in the documentation and/or other materials provided with the
    #    distribution.
    # 
    # THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
    # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
    # THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
    # PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
    # BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
    # OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
    # OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
    # BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
    # WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
    # OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
    # EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136942);
      script_version("1.3");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/05");
    
      script_cve_id("CVE-2020-10030", "CVE-2020-10995", "CVE-2020-12244");
    
      script_name(english:"FreeBSD : powerdns-recursor -- multiple vulnerabilities (f9c5a410-9b4e-11ea-ac3f-6805ca2fa271)");
      script_summary(english:"Checks for updated packages in pkg_info output");
    
      script_set_attribute(
        attribute:"synopsis",
        value:
    "The remote FreeBSD host is missing one or more security-related
    updates."
      );
      script_set_attribute(
        attribute:"description",
        value:
    "PowerDNS Team reports :
    
    CVE-2020-10995: An issue in the DNS protocol has been found that allow
    malicious parties to use recursive DNS services to attack third party
    authoritative name servers. The attack uses a crafted reply by an
    authoritative name server to amplify the resulting traffic between the
    recursive and other authoritative name servers. Both types of service
    can suffer degraded performance as an effect.
    
    CVE-2020-12244: An issue has been found in PowerDNS Recursor 4.1.0
    through 4.3.0 where records in the answer section of a NXDOMAIN
    response lacking an SOA were not properly validated in
    SyncRes::processAnswer. This would allow an attacker in position of
    man-in-the-middle to send a NXDOMAIN answer for a name that does
    exist, bypassing DNSSEC validation.
    
    CVE-2020-10030: An issue has been found in PowerDNS Authoritative
    Server allowing an attacker with enough privileges to change the
    system's hostname to cause disclosure of uninitialized memory content
    via a stack-based out-of-bounds read. It only occurs on systems where
    gethostname() does not null-terminate the returned string if the
    hostname is larger than the supplied buffer. Linux systems are not
    affected because the buffer is always large enough. OpenBSD systems
    are not affected because the returned hostname is always
    null-terminated. Under some conditions this issue can lead to the
    writing of one null-byte out-of-bounds on the stack, causing a denial
    of service or possibly arbitrary code execution."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://doc.powerdns.com/recursor/security-advisories/index.html"
      );
      # https://vuxml.freebsd.org/freebsd/f9c5a410-9b4e-11ea-ac3f-6805ca2fa271.html
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?72d79f2a"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected packages.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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: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:freebsd:freebsd:powerdns-recursor");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/19");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/26");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/28");
      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:"FreeBSD Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("freebsd_package.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
    if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    
    if (pkg_test(save_report:TRUE, pkg:"powerdns-recursor>=4.3.0<4.3.1")) flag++;
    if (pkg_test(save_report:TRUE, pkg:"powerdns-recursor>=4.2.0<4.2.2")) flag++;
    if (pkg_test(save_report:TRUE, pkg:"powerdns-recursor>=4.1.0<4.1.16")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_warning(port:0, extra:pkg_report_get());
      else security_warning(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");
    
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-4691.NASL
    descriptionTwo vulnerabilities have been discovered in PDNS Recursor, a resolving name server; a traffic amplification attack against third-party authoritative name servers (NXNSAttack) and insufficient validation of NXDOMAIN responses lacking an SOA. The version of pdns-recursor in the oldstable distribution (stretch) is no longer supported. If these security issues affect your setup, you should upgrade to the stable distribution (buster).
    last seen2020-05-31
    modified2020-05-22
    plugin id136778
    published2020-05-22
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136778
    titleDebian DSA-4691-1 : pdns-recursor - security update
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Debian Security Advisory DSA-4691. The text 
    # itself is copyright (C) Software in the Public Interest, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136778);
      script_version("1.2");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/26");
    
      script_cve_id("CVE-2020-10995", "CVE-2020-12244");
      script_xref(name:"DSA", value:"4691");
    
      script_name(english:"Debian DSA-4691-1 : pdns-recursor - security update");
      script_summary(english:"Checks dpkg output for the updated package");
    
      script_set_attribute(
        attribute:"synopsis",
        value:"The remote Debian host is missing a security-related update."
      );
      script_set_attribute(
        attribute:"description",
        value:
    "Two vulnerabilities have been discovered in PDNS Recursor, a resolving
    name server; a traffic amplification attack against third-party
    authoritative name servers (NXNSAttack) and insufficient validation of
    NXDOMAIN responses lacking an SOA.
    
    The version of pdns-recursor in the oldstable distribution (stretch)
    is no longer supported. If these security issues affect your setup,
    you should upgrade to the stable distribution (buster)."
      );
      # https://security-tracker.debian.org/tracker/source-package/pdns-recursor
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?51aad11d"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/buster/pdns-recursor"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://www.debian.org/security/2020/dsa-4691"
      );
      script_set_attribute(
        attribute:"solution",
        value:
    "Upgrade the pdns-recursor packages.
    
    For the stable distribution (buster), these problems have been fixed
    in version 4.1.11-1+deb10u1."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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:N/AC:L/PR:N/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:debian:debian_linux:pdns-recursor");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:10.0");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/19");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/21");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/22");
      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:"Debian Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("debian_package.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
    if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    if (deb_check(release:"10.0", prefix:"pdns-recursor", reference:"4.1.11-1+deb10u1")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_warning(port:0, extra:deb_report_get());
      else security_warning(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");