Vulnerabilities > CVE-2018-10903 - Improper Input Validation vulnerability in multiple products

047910
CVSS 5.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
NONE
Availability impact
NONE
network
low complexity
cryptography
redhat
canonical
CWE-20
nessus

Summary

A flaw was found in python-cryptography versions between >=1.9.0 and <2.3. The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries can cause key leakage.

Vulnerable Configurations

Part Description Count
Application
Cryptography
1
Application
Redhat
1
OS
Canonical
1

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-2018-1281.NASL
    descriptionThis update for python-cryptography fixes the following issues : - CVE-2018-10903: The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries could have caused key leakage (bsc#1101820). This update was imported from the SUSE:SLE-15:Update update project.
    last seen2020-06-05
    modified2018-10-26
    plugin id118451
    published2018-10-26
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/118451
    titleopenSUSE Security Update : python-cryptography (openSUSE-2018-1281)
    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-2018-1281.
    #
    # The text description of this plugin is (C) SUSE LLC.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(118451);
      script_version("1.2");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");
    
      script_cve_id("CVE-2018-10903");
    
      script_name(english:"openSUSE Security Update : python-cryptography (openSUSE-2018-1281)");
      script_summary(english:"Check for the openSUSE-2018-1281 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 python-cryptography fixes the following issues :
    
      - CVE-2018-10903: The finalize_with_tag API did not
        enforce a minimum tag length. If a user did not validate
        the input length prior to passing it to
        finalize_with_tag an attacker could craft an invalid
        payload with a shortened tag (e.g. 1 byte) such that
        they would have a 1 in 256 chance of passing the MAC
        check. GCM tag forgeries could have caused key leakage
        (bsc#1101820).
    
    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=1101820"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Update the affected python-cryptography packages."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
      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_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:python-cryptography-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:python-cryptography-debugsource");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:python2-cryptography");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:python2-cryptography-debuginfo");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:python3-cryptography");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:python3-cryptography-debuginfo");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.0");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2018/10/25");
      script_set_attribute(attribute:"plugin_publication_date", value:"2018/10/26");
      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 !~ "^(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:"python-cryptography-debuginfo-2.1.4-lp150.3.3.1") ) flag++;
    if ( rpm_check(release:"SUSE15.0", reference:"python-cryptography-debugsource-2.1.4-lp150.3.3.1") ) flag++;
    if ( rpm_check(release:"SUSE15.0", reference:"python2-cryptography-2.1.4-lp150.3.3.1") ) flag++;
    if ( rpm_check(release:"SUSE15.0", reference:"python2-cryptography-debuginfo-2.1.4-lp150.3.3.1") ) flag++;
    if ( rpm_check(release:"SUSE15.0", reference:"python3-cryptography-2.1.4-lp150.3.3.1") ) flag++;
    if ( rpm_check(release:"SUSE15.0", reference:"python3-cryptography-debuginfo-2.1.4-lp150.3.3.1") ) 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, "python-cryptography-debuginfo / python-cryptography-debugsource / etc");
    }
    
  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-3720-1.NASL
    descriptionIt was discovered that python-cryptography incorrectly handled certain inputs. An attacker could possibly use this to get access to sensitive information. 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 id111269
    published2018-07-24
    reporterUbuntu Security Notice (C) 2018-2019 Canonical, Inc. / NASL script (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/111269
    titleUbuntu 18.04 LTS : python-cryptography vulnerability (USN-3720-1)
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_9E2D0DCF992611E8A92D0050562A4D7B.NASL
    descriptionThe Python Cryptographic Authority (PyCA) project reports : finalize_with_tag() allowed tag truncation by default which can allow tag forgery in some cases. The method now enforces the min_tag_length provided to the GCM constructor
    last seen2020-06-01
    modified2020-06-02
    plugin id111541
    published2018-08-06
    reporterThis script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/111541
    titleFreeBSD : py-cryptography -- tag forgery vulnerability (9e2d0dcf-9926-11e8-a92d-0050562a4d7b)
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2020-0790-1.NASL
    descriptionThis update for python-cffi, python-cryptography and python-xattr fixes the following issues : Security issue fixed : CVE-2018-10903: Fixed GCM tag forgery via truncated tag in finalize_with_tag API (bsc#1101820). Non-security issues fixed : python-cffi was updated to 1.11.2 (bsc#1138748, jsc#ECO-1256, jsc#PM-1598): fixed a build failure on i586 (bsc#1111657) Salt was unable to highstate in snapshot 20171129 (bsc#1070737) Update pytest in spec to add c directory tests in addition to testing directory. Update to 1.11.1: Fix tests, remove deprecated C API usage Fix (hack) for 3.6.0/3.6.1/3.6.2 giving incompatible binary extensions (cpython issue #29943) Fix for 3.7.0a1+ Update to 1.11.0: Support the modern standard types char16_t and char32_t. These work like wchar_t: they represent one unicode character, or when used as charN_t * or charN_t[] they represent a unicode string. The difference with wchar_t is that they have a known, fixed size. They should work at all places that used to work with wchar_t (please report an issue if I missed something). Note that with set_source(), you need to make sure that these types are actually defined by the C source you provide (if used in cdef()). Support the C99 types float _Complex and double _Complex. Note that libffi doesn
    last seen2020-03-31
    modified2020-03-26
    plugin id134937
    published2020-03-26
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/134937
    titleSUSE SLES12 Security Update : python-cffi, python-cryptography, python-xattr (SUSE-SU-2020:0790-1)
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2019-857.NASL
    descriptionThis update for python-cryptography fixes the following issues : - CVE-2018-10903: The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries could have caused key leakage (bsc#1101820). This update was imported from the SUSE:SLE-15:Update update project.
    last seen2020-06-01
    modified2020-06-02
    plugin id123358
    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/123358
    titleopenSUSE Security Update : python-cryptography (openSUSE-2019-857)
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2018-3392-1.NASL
    descriptionThis update for python-cryptography fixes the following issues : CVE-2018-10903: The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries could have caused key leakage (bsc#1101820). 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 seen2020-03-18
    modified2019-01-02
    plugin id120144
    published2019-01-02
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120144
    titleSUSE SLED15 / SLES15 Security Update : python-cryptography (SUSE-SU-2018:3392-1)
  • NASL familyPhotonOS Local Security Checks
    NASL idPHOTONOS_PHSA-2019-2_0-0198_PYTHON.NASL
    descriptionAn update of the python package has been released.
    last seen2020-06-01
    modified2020-06-02
    plugin id132977
    published2020-01-16
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/132977
    titlePhoton OS 2.0: Python PHSA-2019-2.0-0198
  • NASL familySuSE Local Security Checks
    NASL idSUSE_SU-2020-0792-1.NASL
    descriptionThis update for python-cffi, python-cryptography fixes the following issues : Security issue fixed : CVE-2018-10903: Fixed GCM tag forgery via truncated tag in finalize_with_tag API (bsc#1101820). Non-security issues fixed : python-cffi was updated to 1.11.2 (bsc#1138748, jsc#ECO-1256, jsc#PM-1598): fixed a build failure on i586 (bsc#1111657) Salt was unable to highstate in snapshot 20171129 (bsc#1070737) Update pytest in spec to add c directory tests in addition to testing directory. update to version 1.11.2 : - Fix Windows issue with managing the thread-state on CPython 3.0 to 3.5 Update pytest in spec to add c directory tests in addition to testing directory. Omit test_init_once_multithread tests as they rely on multiple threads finishing in a given time. Returns sporadic pass/fail within build. Update to 1.11.1 : - Fix tests, remove deprecated C API usage - Fix (hack) for 3.6.0/3.6.1/3.6.2 giving incompatible binary extensions (cpython issue #29943) - Fix for 3.7.0a1+ Update to 1.11.0 : - Support the modern standard types char16_t and char32_t. These work like wchar_t: they represent one unicode character, or when used as charN_t * or charN_t[] they represent a unicode string. The difference with wchar_t is that they have a known, fixed size. They should work at all places that used to work with wchar_t (please report an issue if I missed something). Note that with set_source(), you need to make sure that these types are actually defined by the C source you provide (if used in cdef()). - Support the C99 types float _Complex and double _Complex. Note that libffi doesn
    last seen2020-03-31
    modified2020-03-26
    plugin id134938
    published2020-03-26
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/134938
    titleSUSE SLES12 Security Update : python-cffi, python-cryptography (SUSE-SU-2020:0792-1)

Redhat

advisories
rhsa
idRHSA-2018:3600
rpms
  • python-cryptography-debuginfo-0:2.1.4-3.el7ost
  • python2-cryptography-0:2.1.4-3.el7ost