Vulnerabilities > CVE-2019-12855 - Improper Certificate Validation vulnerability in Twistedmatrix Twisted

047910
CVSS 7.4 - HIGH
Attack vector
NETWORK
Attack complexity
HIGH
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
NONE
network
high complexity
twistedmatrix
CWE-295
nessus
NVD
Published: 2019-06-16
Updated: 2023-11-07

Summary

In words.protocols.jabber.xmlstream in Twisted through 19.2.1, XMPP support did not verify certificates when used with TLS, allowing an attacker to MITM connections.

Vulnerable Configurations

Part Description Count
Application
Twistedmatrix
46

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Creating a Rogue Certificate Authority Certificate
    An attacker exploits a weakness in the MD5 hash algorithm (weak collision resistance) to generate a certificate signing request (CSR) that contains collision blocks in the "to be signed" part. The attacker specially crafts two different, but valid X.509 certificates that when hashed with the MD5 algorithm would yield the same value. The attacker then sends the CSR for one of the certificates to the Certification Authority which uses the MD5 hashing algorithm. That request is completely valid and the Certificate Authority issues an X.509 certificate to the attacker which is signed with its private key. An attacker then takes that signed blob and inserts it into another X.509 certificate that the attacker generated. Due to the MD5 collision, both certificates, though different, hash to the same value and so the signed blob works just as well in the second certificate. The net effect is that the attackers' second X.509 certificate, which the Certification Authority has never seen, is now signed and validated by that Certification Authority. To make the attack more interesting, the second certificate could be not just a regular certificate, but rather itself a signing certificate. Thus the attacker is able to start their own Certification Authority that is anchored in its root of trust in the legitimate Certification Authority that has signed the attackers' first X.509 certificate. If the original Certificate Authority was accepted by default by browsers, so will now the Certificate Authority set up by the attacker and of course any certificates that it signs. So the attacker is now able to generate any SSL certificates to impersonate any web server, and the user's browser will not issue any warning to the victim. This can be used to compromise HTTPS communications and other types of systems where PKI and X.509 certificates may be used (e.g., VPN, IPSec) .

Nessus

  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2019-2212-1.NASL
    descriptionThis update for python-Twisted fixes the following issues : Security issue fixed : CVE-2019-12855: Fixed TLS certificate verification to protecting against MITM attacks (bsc#1138461). Note that Tenable Network Security has extracted the preceding description block directly from the SUSE 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 id128145
    published2019-08-26
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/128145
    titleSUSE SLED15 / SLES15 Security Update : python-Twisted (SUSE-SU-2019:2212-1)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from SUSE update advisory SUSE-SU-2019:2212-1.
# The text itself is copyright (C) SUSE.
#

include("compat.inc");

if (description)
{
  script_id(128145);
  script_version("1.3");
  script_cvs_date("Date: 2019/12/31");

  script_cve_id("CVE-2019-12855");

  script_name(english:"SUSE SLED15 / SLES15 Security Update : python-Twisted (SUSE-SU-2019:2212-1)");
  script_summary(english:"Checks rpm output for the updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote SUSE host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"This update for python-Twisted fixes the following issues :

Security issue fixed :

CVE-2019-12855: Fixed TLS certificate verification to protecting
against MITM attacks (bsc#1138461).

Note that Tenable Network Security has extracted the preceding
description block directly from the SUSE 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.suse.com/show_bug.cgi?id=1138461"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2019-12855/"
  );
  # https://www.suse.com/support/update/announcement/2019/suse-su-20192212-1/
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?750fc62c"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"To install this SUSE Security Update use the SUSE recommended
installation methods like YaST online_update or 'zypper patch'.

Alternatively you can run the command listed for your product :

SUSE Linux Enterprise Module for Open Buildservice Development Tools
15-SP1:zypper in -t patch
SUSE-SLE-Module-Development-Tools-OBS-15-SP1-2019-2212=1

SUSE Linux Enterprise Module for Open Buildservice Development Tools
15:zypper in -t patch
SUSE-SLE-Module-Development-Tools-OBS-15-2019-2212=1"
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/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:H/PR:N/UI:N/S:U/C:H/I:H/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:suse_linux:python-Twisted-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:python-Twisted-debugsource");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:python-Twisted-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:python2-Twisted");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:python2-Twisted-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:python3-Twisted");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:suse_linux:python3-Twisted-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:suse_linux:15");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/06/16");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/08/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/08/26");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2019 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/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)") audit(AUDIT_OS_NOT, "SUSE");
os_ver = pregmatch(pattern: "^(SLE(S|D)\d+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "SUSE");
os_ver = os_ver[1];
if (! preg(pattern:"^(SLED15|SLES15)$", string:os_ver)) audit(AUDIT_OS_NOT, "SUSE SLED15 / SLES15", "SUSE " + os_ver);

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 " + os_ver, cpu);

sp = get_kb_item("Host/SuSE/patchlevel");
if (isnull(sp)) sp = "0";
if (os_ver == "SLES15" && (! preg(pattern:"^(0|1)$", string:sp))) audit(AUDIT_OS_NOT, "SLES15 SP0/1", os_ver + " SP" + sp);
if (os_ver == "SLED15" && (! preg(pattern:"^(0|1)$", string:sp))) audit(AUDIT_OS_NOT, "SLED15 SP0/1", os_ver + " SP" + sp);


flag = 0;
if (rpm_check(release:"SLES15", sp:"1", reference:"python-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"1", reference:"python-Twisted-debugsource-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"1", reference:"python-Twisted-doc-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"1", reference:"python2-Twisted-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"1", reference:"python2-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"1", reference:"python3-Twisted-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"1", reference:"python3-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"0", reference:"python-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"0", reference:"python-Twisted-debugsource-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"0", reference:"python-Twisted-doc-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"0", reference:"python2-Twisted-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"0", reference:"python2-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"0", reference:"python3-Twisted-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLES15", sp:"0", reference:"python3-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"1", reference:"python-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"1", reference:"python-Twisted-debugsource-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"1", reference:"python-Twisted-doc-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"1", reference:"python2-Twisted-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"1", reference:"python2-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"1", reference:"python3-Twisted-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"1", reference:"python3-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"0", reference:"python-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"0", reference:"python-Twisted-debugsource-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"0", reference:"python-Twisted-doc-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"0", reference:"python2-Twisted-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"0", reference:"python2-Twisted-debuginfo-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"0", reference:"python3-Twisted-17.9.0-3.6.1")) flag++;
if (rpm_check(release:"SLED15", sp:"0", reference:"python3-Twisted-debuginfo-17.9.0-3.6.1")) 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, "python-Twisted");
}
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2019-D480909528.NASL
    descriptionSecurity fix for CVE-2019-12855. Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. 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 id127875
    published2019-08-14
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/127875
    titleFedora 30 : python-twisted (2019-d480909528)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory FEDORA-2019-d480909528.
#

include("compat.inc");

if (description)
{
  script_id(127875);
  script_version("1.3");
  script_cvs_date("Date: 2020/01/02");

  script_cve_id("CVE-2019-12855");
  script_xref(name:"FEDORA", value:"2019-d480909528");

  script_name(english:"Fedora 30 : python-twisted (2019-d480909528)");
  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:
"Security fix for CVE-2019-12855.

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora update system website.
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://bodhi.fedoraproject.org/updates/FEDORA-2019-d480909528"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected python-twisted package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/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:H/PR:N/UI:N/S:U/C:H/I:H/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:fedoraproject:fedora:python-twisted");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:30");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/06/16");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/08/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/08/14");
  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:"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 = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! preg(pattern:"^30([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 30", "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:"FC30", reference:"python-twisted-19.2.1-3.fc30")) flag++;


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "python-twisted");
}
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2019-2453-1.NASL
    descriptionThis update for python-Twisted fixes the following issues : Security issue fixed : CVE-2019-12855: Fixed TLS certificate verification to protecting against MITM attacks (bsc#1138461). Note that Tenable Network Security has extracted the preceding description block directly from the SUSE 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 id129349
    published2019-09-25
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/129349
    titleSUSE SLES12 Security Update : python-Twisted (SUSE-SU-2019:2453-1)
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-4308-1.NASL
    descriptionit was discovered that Twisted incorrectly validated or sanitized certain URIs or HTTP methods. A remote attacker could use this issue to inject invalid characters and possibly perform header injection attacks. (CVE-2019-12387) It was discovered that Twisted incorrectly verified XMPP TLS certificates. A remote attacker could possibly use this issue to perform a man-in-the-middle attack and obtain sensitive information. (CVE-2019-12855) It was discovered that Twisted incorrectly handled HTTP/2 connections. A remote attacker could possibly use this issue to cause Twisted to hang or consume resources, leading to a denial of service. This issue only affected Ubuntu 18.04 LTS and Ubuntu 19.10. (CVE-2019-9512, CVE-2019-9514, CVE-2019-9515) Jake Miller and ZeddYu Lu discovered that Twisted incorrectly handled certain content-length headers. A remote attacker could possibly use this issue to perform HTTP request splitting attacks. (CVE-2020-10108, CVE-2020-10109). 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 seen2020-03-26
    modified2020-03-20
    plugin id134758
    published2020-03-20
    reporterUbuntu Security Notice (C) 2020 Canonical, Inc. / NASL script (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/134758
    titleUbuntu 16.04 LTS / 18.04 LTS / 19.10 : twisted vulnerabilities (USN-4308-1) (Ping Flood) (Reset Flood) (Settings Flood)
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2019-2068.NASL
    descriptionThis update for python-Twisted fixes the following issues : Security issue fixed : - CVE-2019-12855: Fixed TLS certificate verification to protecting against MITM attacks (bsc#1138461). This update was imported from the SUSE:SLE-15:Update update project.
    last seen2020-06-01
    modified2020-06-02
    plugin id128538
    published2019-09-06
    reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/128538
    titleopenSUSE Security Update : python-Twisted (openSUSE-2019-2068)

References