Vulnerabilities > CVE-2018-12356 - Improper Verification of Cryptographic Signature vulnerability in Simple Password Store Project Simple Password Store

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
simple-password-store-project
CWE-347
nessus

Summary

An issue was discovered in password-store.sh in pass in Simple Password Store 1.7.x before 1.7.2. The signature verification routine parses the output of GnuPG with an incomplete regular expression, which allows remote attackers to spoof file signatures on configuration files and extension scripts. Modifying the configuration file allows the attacker to inject additional encryption keys under their control, thereby disclosing passwords to the attacker. Modifying the extension scripts allows the attacker arbitrary code execution.

Vulnerable Configurations

Part Description Count
Application
Simple_Password_Store_Project
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-A89844963C.NASL
    descriptionUpdate to new upstream release 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 id120691
    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/120691
    titleFedora 28 : pass (2018-a89844963c)
    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-a89844963c.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(120691);
      script_version("1.4");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");
    
      script_cve_id("CVE-2018-12356");
      script_xref(name:"FEDORA", value:"2018-a89844963c");
    
      script_name(english:"Fedora 28 : pass (2018-a89844963c)");
      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:
    "Update to new upstream release
    
    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-a89844963c"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected pass package.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
      script_set_cvss_temporal_vector("CVSS2#E:POC/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:H/A:H");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:pass");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:28");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2018/06/15");
      script_set_attribute(attribute:"patch_publication_date", value:"2018/06/23");
      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:"pass-1.7.2-1.fc28")) flag++;
    
    
    if (flag)
    {
      security_report_v4(
        port       : 0,
        severity   : SECURITY_HOLE,
        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, "pass");
    }
    
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_53EB9E1E701411E88B1F3065EC8FD3EC.NASL
    descriptionJason A. Donenfeld reports : Markus Brinkmann discovered that [the] parsing of gpg command line output with regexes isn
    last seen2020-06-01
    modified2020-06-02
    plugin id110540
    published2018-06-15
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/110540
    titleFreeBSD : password-store -- GPG parsing vulnerabilities (53eb9e1e-7014-11e8-8b1f-3065ec8fd3ec)
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-A3E631B454.NASL
    descriptionUpdate to new upstream release 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
    modified2018-06-25
    plugin id110669
    published2018-06-25
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/110669
    titleFedora 27 : pass (2018-a3e631b454)

The Hacker News

idTHN:20BF2C23D315483B3CA9190D047C1212
last seen2019-04-30
modified2019-04-30
published2019-04-30
reporterThe Hacker News
sourcehttps://thehackernews.com/2019/04/email-signature-spoofing.html
titleOver Dozen Popular Email Clients Found Vulnerable to Signature Spoofing Attacks