Vulnerabilities > CVE-2018-7711 - Improper Verification of Cryptographic Signature vulnerability in multiple products

047910
CVSS 6.8 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL

Summary

HTTPRedirect.php in the saml2 library in SimpleSAMLphp before 1.15.4 has an incorrect check of return values in the signature validation utilities, allowing an attacker to get invalid signatures accepted as valid by forcing an error during validation. This occurs because of a dependency on PHP functionality that interprets a -1 error code as a true boolean value.

Vulnerable Configurations

Part Description Count
Application
Simplesamlphp
129
OS
Debian
1

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 familyFedora Local Security Checks
    NASL idFEDORA_2018-8CDA2309D6.NASL
    description - [SSPSA 201803-01 / CVE-2018-7711](https://simplesamlphp.org/security/201803 -01) - [SSPSA 201802-01 / CVE-2018-7644](https://simplesamlphp.org/security/201802 -01) - [SSPSA 201801-01 / CVE-2018-6519](https://simplesamlphp.org/security/201801 -01) 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 seen2020-06-05
    modified2019-01-03
    plugin id120598
    published2019-01-03
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120598
    titleFedora 28 : php-simplesamlphp-saml2_3 (2018-8cda2309d6)
    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 FEDORA-2018-8cda2309d6.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(120598);
      script_version("1.4");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");
    
      script_cve_id("CVE-2018-6519", "CVE-2018-7644", "CVE-2018-7711");
      script_xref(name:"FEDORA", value:"2018-8cda2309d6");
    
      script_name(english:"Fedora 28 : php-simplesamlphp-saml2_3 (2018-8cda2309d6)");
      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:
    "  - [SSPSA 201803-01 /
        CVE-2018-7711](https://simplesamlphp.org/security/201803
        -01)
    
      - [SSPSA 201802-01 /
        CVE-2018-7644](https://simplesamlphp.org/security/201802
        -01)
    
      - [SSPSA 201801-01 /
        CVE-2018-6519](https://simplesamlphp.org/security/201801
        -01)
    
    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-2018-8cda2309d6"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Update the affected php-simplesamlphp-saml2_3 package."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/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:H/PR:N/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:fedoraproject:fedora:php-simplesamlphp-saml2_3");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:28");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2018/02/02");
      script_set_attribute(attribute:"patch_publication_date", value:"2018/03/30");
      script_set_attribute(attribute:"plugin_publication_date", value:"2019/01/03");
      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:"^28([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 28", "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:"FC28", reference:"php-simplesamlphp-saml2_3-3.1.4-3.fc28")) 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, "php-simplesamlphp-saml2_3");
    }
    
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-37E28670F2.NASL
    description - [SSPSA 201803-01 / CVE-2018-7711](https://simplesamlphp.org/security/201803 -01) - [SSPSA 201802-01 / CVE-2018-7644](https://simplesamlphp.org/security/201802 -01) - [SSPSA 201801-01 / CVE-2018-6519](https://simplesamlphp.org/security/201801 -01) 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 seen2020-06-05
    modified2018-03-27
    plugin id108615
    published2018-03-27
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/108615
    titleFedora 27 : php-simplesamlphp-saml2_3 (2018-37e28670f2)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-0EE228DA17.NASL
    description - [SSPSA 201803-01 / CVE-2018-7711](https://simplesamlphp.org/security/201803 -01) - [SSPSA 201802-01 / CVE-2018-7644](https://simplesamlphp.org/security/201802 -01) - [SSPSA 201801-01 / CVE-2018-6519](https://simplesamlphp.org/security/201801 -01) 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 seen2020-06-05
    modified2019-01-03
    plugin id120236
    published2019-01-03
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120236
    titleFedora 28 : php-simplesamlphp-saml2_1 (2018-0ee228da17)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-F4AB4D96F9.NASL
    description - [SSPSA 201803-01 / CVE-2018-7711](https://simplesamlphp.org/security/201803 -01) - [SSPSA 201802-01 / CVE-2018-7644](https://simplesamlphp.org/security/201802 -01) - [SSPSA 201801-01 / CVE-2018-6519](https://simplesamlphp.org/security/201801 -01) 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 seen2020-06-05
    modified2018-03-27
    plugin id108622
    published2018-03-27
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/108622
    titleFedora 26 : php-simplesamlphp-saml2 (2018-f4ab4d96f9)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-96601292A2.NASL
    description - [SSPSA 201803-01 / CVE-2018-7711](https://simplesamlphp.org/security/201803 -01) - [SSPSA 201802-01 / CVE-2018-7644](https://simplesamlphp.org/security/201802 -01) - [SSPSA 201801-01 / CVE-2018-6519](https://simplesamlphp.org/security/201801 -01) 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 seen2020-06-05
    modified2018-03-27
    plugin id108619
    published2018-03-27
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/108619
    titleFedora 27 : php-simplesamlphp-saml2_1 (2018-96601292a2)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-6DB40B0C37.NASL
    description - [SSPSA 201803-01 / CVE-2018-7711](https://simplesamlphp.org/security/201803 -01) - [SSPSA 201802-01 / CVE-2018-7644](https://simplesamlphp.org/security/201802 -01) - [SSPSA 201801-01 / CVE-2018-6519](https://simplesamlphp.org/security/201801 -01) 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 seen2020-06-05
    modified2018-03-27
    plugin id108618
    published2018-03-27
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/108618
    titleFedora 27 : php-simplesamlphp-saml2 (2018-6db40b0c37)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-D809BD2FD6.NASL
    description - [SSPSA 201803-01 / CVE-2018-7711](https://simplesamlphp.org/security/201803 -01) - [SSPSA 201802-01 / CVE-2018-7644](https://simplesamlphp.org/security/201802 -01) - [SSPSA 201801-01 / CVE-2018-6519](https://simplesamlphp.org/security/201801 -01) 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 seen2020-06-05
    modified2018-03-27
    plugin id108620
    published2018-03-27
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/108620
    titleFedora 26 : php-simplesamlphp-saml2_1 (2018-d809bd2fd6)
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DLA-1314.NASL
    descriptionCure53 discovered that in SimpleSAMLphp, in rare circumstances an invalid signature on the SAML 2.0 HTTP Redirect binding could be considered valid. Additionally this update fixes a regression introduced in DLA-1298 by the backported patch for SSA-201802-01/CVE-2018-7644. For Debian 7
    last seen2020-03-17
    modified2018-03-27
    plugin id108604
    published2018-03-27
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/108604
    titleDebian DLA-1314-1 : simplesamlphp security update
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-85CB15BEFD.NASL
    description - [SSPSA 201803-01 / CVE-2018-7711](https://simplesamlphp.org/security/201803 -01) - [SSPSA 201802-01 / CVE-2018-7644](https://simplesamlphp.org/security/201802 -01) - [SSPSA 201801-01 / CVE-2018-6519](https://simplesamlphp.org/security/201801 -01) 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 seen2020-06-05
    modified2019-01-03
    plugin id120582
    published2019-01-03
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120582
    titleFedora 28 : php-simplesamlphp-saml2 (2018-85cb15befd)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-F2097D8937.NASL
    description - [SSPSA 201803-01 / CVE-2018-7711](https://simplesamlphp.org/security/201803 -01) - [SSPSA 201802-01 / CVE-2018-7644](https://simplesamlphp.org/security/201802 -01) - [SSPSA 201801-01 / CVE-2018-6519](https://simplesamlphp.org/security/201801 -01) 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 seen2020-06-05
    modified2018-03-27
    plugin id108621
    published2018-03-27
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/108621
    titleFedora 26 : php-simplesamlphp-saml2_3 (2018-f2097d8937)