Vulnerabilities > CVE-2011-2189 - Resource Exhaustion vulnerability in multiple products

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
network
low complexity
linux
redhat
canonical
debian
CWE-400
nessus
exploit available

Summary

net/core/net_namespace.c in the Linux kernel 2.6.32 and earlier does not properly handle a high rate of creation and cleanup of network namespaces, which makes it easier for remote attackers to cause a denial of service (memory consumption) via requests to a daemon that requires a separate namespace per connection, as demonstrated by vsftpd.

Vulnerable Configurations

Part Description Count
OS
Linux
1107
OS
Redhat
2
OS
Canonical
4
OS
Debian
3

Common Attack Pattern Enumeration and Classification (CAPEC)

  • XML Ping of the Death
    An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
  • XML Entity Expansion
    An attacker submits an XML document to a target application where the XML document uses nested entity expansion to produce an excessively large output XML. XML allows the definition of macro-like structures that can be used to simplify the creation of complex structures. However, this capability can be abused to create excessive demands on a processor's CPU and memory. A small number of nested expansions can result in an exponential growth in demands on memory.
  • Inducing Account Lockout
    An attacker leverages the security functionality of the system aimed at thwarting potential attacks to launch a denial of service attack against a legitimate system user. Many systems, for instance, implement a password throttling mechanism that locks an account after a certain number of incorrect log in attempts. An attacker can leverage this throttling mechanism to lock a legitimate user out of their own account. The weakness that is being leveraged by an attacker is the very security feature that has been put in place to counteract attacks.
  • Violating Implicit Assumptions Regarding XML Content (aka XML Denial of Service (XDoS))
    XML Denial of Service (XDoS) can be applied to any technology that utilizes XML data. This is, of course, most distributed systems technology including Java, .Net, databases, and so on. XDoS is most closely associated with web services, SOAP, and Rest, because remote service requesters can post malicious XML payloads to the service provider designed to exhaust the service provider's memory, CPU, and/or disk space. The main weakness in XDoS is that the service provider generally must inspect, parse, and validate the XML messages to determine routing, workflow, security considerations, and so on. It is exactly these inspection, parsing, and validation routines that XDoS targets. There are three primary attack vectors that XDoS can navigate Target CPU through recursion: attacker creates a recursive payload and sends to service provider Target memory through jumbo payloads: service provider uses DOM to parse XML. DOM creates in memory representation of XML document, but when document is very large (for example, north of 1 Gb) service provider host may exhaust memory trying to build memory objects. XML Ping of death: attack service provider with numerous small files that clog the system. All of the above attacks exploit the loosely coupled nature of web services, where the service provider has little to no control over the service requester and any messages the service requester sends.

Exploit-Db

descriptionLinux Kernel Network Namespace Remote Denial of Service Vulnerability. CVE-2011-2189. Dos exploit for linux platform
idEDB-ID:36425
last seen2016-02-04
modified2011-12-06
published2011-12-06
reporterSerge Hallyn
sourcehttps://www.exploit-db.com/download/36425/
titleLinux Kernel Network Namespace Remote Denial of Service Vulnerability

Nessus

  • NASL familyUbuntu Local Security Checks
    NASL idUBUNTU_USN-1288-1.NASL
    descriptionIt was discovered that the 2.6.35 and earlier Linux kernel does not properly handle a high rate of creation and cleanup of network namespaces, which makes it easier for remote attackers to cause a denial of service (memory consumption) in applications that require a separate namespace per connection, like vsftpd. This update adjusts vsftpd to only use network namespaces on kernels that are known to be not affected. 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 id57038
    published2011-12-07
    reporterUbuntu Security Notice (C) 2011-2019 Canonical, Inc. / NASL script (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/57038
    titleUbuntu 10.04 LTS / 10.10 / 11.04 / 11.10 : vsftpd vulnerability (USN-1288-1)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from Ubuntu Security Notice USN-1288-1. The text 
    # itself is copyright (C) Canonical, Inc. See 
    # <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
    # trademark of Canonical, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(57038);
      script_version("1.6");
      script_cvs_date("Date: 2019/09/19 12:54:27");
    
      script_cve_id("CVE-2011-2189");
      script_xref(name:"USN", value:"1288-1");
    
      script_name(english:"Ubuntu 10.04 LTS / 10.10 / 11.04 / 11.10 : vsftpd vulnerability (USN-1288-1)");
      script_summary(english:"Checks dpkg output for updated package.");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote Ubuntu host is missing a security-related patch."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "It was discovered that the 2.6.35 and earlier Linux kernel does not
    properly handle a high rate of creation and cleanup of network
    namespaces, which makes it easier for remote attackers to cause a
    denial of service (memory consumption) in applications that require a
    separate namespace per connection, like vsftpd. This update adjusts
    vsftpd to only use network namespaces on kernels that are known to be
    not affected.
    
    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."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://usn.ubuntu.com/1288-1/"
      );
      script_set_attribute(
        attribute:"solution", 
        value:"Update the affected vsftpd package."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:vsftpd");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:10.04:-:lts");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:10.10");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:11.04");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:11.10");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2011/10/10");
      script_set_attribute(attribute:"patch_publication_date", value:"2011/12/06");
      script_set_attribute(attribute:"plugin_publication_date", value:"2011/12/07");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"Ubuntu Security Notice (C) 2011-2019 Canonical, Inc. / NASL script (C) 2011-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"Ubuntu Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("ubuntu.inc");
    include("misc_func.inc");
    
    if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    release = get_kb_item("Host/Ubuntu/release");
    if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
    release = chomp(release);
    if (! preg(pattern:"^(10\.04|10\.10|11\.04|11\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 10.04 / 10.10 / 11.04 / 11.10", "Ubuntu " + release);
    if ( ! get_kb_item("Host/Debian/dpkg-l") ) 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, "Ubuntu", cpu);
    
    flag = 0;
    
    if (ubuntu_check(osver:"10.04", pkgname:"vsftpd", pkgver:"2.2.2-3ubuntu6.3")) flag++;
    if (ubuntu_check(osver:"10.10", pkgname:"vsftpd", pkgver:"2.3.0~pre2-4ubuntu2.3")) flag++;
    if (ubuntu_check(osver:"11.04", pkgname:"vsftpd", pkgver:"2.3.2-3ubuntu4.1")) flag++;
    if (ubuntu_check(osver:"11.10", pkgname:"vsftpd", pkgver:"2.3.2-3ubuntu5.1")) flag++;
    
    if (flag)
    {
      security_report_v4(
        port       : 0,
        severity   : SECURITY_HOLE,
        extra      : ubuntu_report_get()
      );
      exit(0);
    }
    else
    {
      tested = ubuntu_pkg_tests_get();
      if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
      else audit(AUDIT_PACKAGE_NOT_INSTALLED, "vsftpd");
    }
    
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-2305.NASL
    descriptionTwo security issue have been discovered that affect vsftpd, a lightweight, efficient FTP server written for security. - CVE-2011-2189 It was discovered that Linux kernels < 2.6.35 are considerably slower in releasing than in the creation of network namespaces. As a result of this and because vsftpd is using this feature as a security enhancement to provide network isolation for connections, it is possible to cause denial of service conditions due to excessive memory allocations by the kernel. This is technically no vsftpd flaw, but a kernel issue. However, this feature has legitimate use cases and backporting the specific kernel patch is too intrusive. Additionally, a local attacker requires the CAP_SYS_ADMIN capability to abuse this functionality. Therefore, as a fix, a kernel version check has been added to vsftpd in order to disable this feature for kernels < 2.6.35. - CVE-2011-0762 Maksymilian Arciemowicz discovered that vsftpd is incorrectly handling certain glob expressions in STAT commands. This allows a remote authenticated attacker to conduct denial of service attacks (excessive CPU and process slot exhaustion) via crafted STAT commands.
    last seen2020-03-17
    modified2011-09-20
    plugin id56231
    published2011-09-20
    reporterThis script is Copyright (C) 2011-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/56231
    titleDebian DSA-2305-1 : vsftpd - denial of service
    code
    #%NASL_MIN_LEVEL 80502
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Debian Security Advisory DSA-2305. The text 
    # itself is copyright (C) Software in the Public Interest, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(56231);
      script_version("1.11");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/03/12");
    
      script_cve_id("CVE-2011-0762", "CVE-2011-2189");
      script_bugtraq_id(46617);
      script_xref(name:"DSA", value:"2305");
    
      script_name(english:"Debian DSA-2305-1 : vsftpd - denial of service");
      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 security issue have been discovered that affect vsftpd, a
    lightweight, efficient FTP server written for security.
    
      - CVE-2011-2189
        It was discovered that Linux kernels < 2.6.35 are
        considerably slower in releasing than in the creation of
        network namespaces. As a result of this and because
        vsftpd is using this feature as a security enhancement
        to provide network isolation for connections, it is
        possible to cause denial of service conditions due to
        excessive memory allocations by the kernel. This is
        technically no vsftpd flaw, but a kernel issue. However,
        this feature has legitimate use cases and backporting
        the specific kernel patch is too intrusive.
        Additionally, a local attacker requires the
        CAP_SYS_ADMIN capability to abuse this functionality.
        Therefore, as a fix, a kernel version check has been
        added to vsftpd in order to disable this feature for
        kernels < 2.6.35.
    
      - CVE-2011-0762
        Maksymilian Arciemowicz discovered that vsftpd is
        incorrectly handling certain glob expressions in STAT
        commands. This allows a remote authenticated attacker to
        conduct denial of service attacks (excessive CPU and
        process slot exhaustion) via crafted STAT commands."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=622741"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=629373"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://security-tracker.debian.org/tracker/CVE-2011-2189"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://security-tracker.debian.org/tracker/CVE-2011-0762"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://security-tracker.debian.org/tracker/CVE-2011-2189"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/squeeze/vsftpd"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://www.debian.org/security/2011/dsa-2305"
      );
      script_set_attribute(
        attribute:"solution", 
        value:
    "Upgrade the vsftpd packages.
    
    For the oldstable distribution (lenny), this problem has been fixed in
    version 2.0.7-1+lenny1.
    
    For the stable distribution (squeeze), this problem has been fixed in
    version 2.3.2-3+squeeze2. Please note that CVE-2011-2189 does not
    affect the lenny version."
      );
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
      script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/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:debian:debian_linux:vsftpd");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:5.0");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:6.0");
    
      script_set_attribute(attribute:"patch_publication_date", value:"2011/09/19");
      script_set_attribute(attribute:"plugin_publication_date", value:"2011/09/20");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2011-2020 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:"5.0", prefix:"vsftpd", reference:"2.0.7-1+lenny1")) flag++;
    if (deb_check(release:"6.0", prefix:"vsftpd", reference:"2.3.2-3+squeeze2")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_hole(port:0, extra:deb_report_get());
      else security_hole(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");
    

References