CVE-2016-10142 (GCVE-0-2016-10142)
Vulnerability from cvelistv5
Published
2017-01-14 06:56
Modified
2024-08-06 03:14
Severity ?
Summary
An issue was discovered in the IPv6 protocol specification, related to ICMP Packet Too Big (PTB) messages. (The scope of this CVE is all affected IPv6 implementations from all vendors.) The security implications of IP fragmentation have been discussed at length in [RFC6274] and [RFC7739]. An attacker can leverage the generation of IPv6 atomic fragments to trigger the use of fragmentation in an arbitrary IPv6 flow (in scenarios in which actual fragmentation of packets is not needed) and can subsequently perform any type of fragmentation-based attack against legacy IPv6 nodes that do not implement [RFC6946]. That is, employing fragmentation where not actually needed allows for fragmentation-based attack vectors to be employed, unnecessarily. We note that, unfortunately, even nodes that already implement [RFC6946] can be subject to DoS attacks as a result of the generation of IPv6 atomic fragments. Let us assume that Host A is communicating with Host B and that, as a result of the widespread dropping of IPv6 packets that contain extension headers (including fragmentation) [RFC7872], some intermediate node filters fragments between Host B and Host A. If an attacker sends a forged ICMPv6 PTB error message to Host B, reporting an MTU smaller than 1280, this will trigger the generation of IPv6 atomic fragments from that moment on (as required by [RFC2460]). When Host B starts sending IPv6 atomic fragments (in response to the received ICMPv6 PTB error message), these packets will be dropped, since we previously noted that IPv6 packets with extension headers were being dropped between Host B and Host A. Thus, this situation will result in a DoS scenario. Another possible scenario is that in which two BGP peers are employing IPv6 transport and they implement Access Control Lists (ACLs) to drop IPv6 fragments (to avoid control-plane attacks). If the aforementioned BGP peers drop IPv6 fragments but still honor received ICMPv6 PTB error messages, an attacker could easily attack the corresponding peering session by simply sending an ICMPv6 PTB message with a reported MTU smaller than 1280 bytes. Once the attack packet has been sent, the aforementioned routers will themselves be the ones dropping their own traffic.
References
cve@mitre.orghttp://rhn.redhat.com/errata/RHSA-2017-0817.html
cve@mitre.orghttp://www.securityfocus.com/bid/95797
cve@mitre.orghttp://www.securitytracker.com/id/1038256
cve@mitre.orghttps://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA43730
cve@mitre.orghttps://support.f5.com/csp/article/K57211290?utm_source=f5support&amp%3Butm_medium=RSS
cve@mitre.orghttps://tools.ietf.org/html/draft-ietf-6man-deprecate-atomfrag-generation-08Third Party Advisory
cve@mitre.orghttps://tools.ietf.org/html/rfc8021Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108http://rhn.redhat.com/errata/RHSA-2017-0817.html
af854a3a-2127-422b-91ae-364da2661108http://www.securityfocus.com/bid/95797
af854a3a-2127-422b-91ae-364da2661108http://www.securitytracker.com/id/1038256
af854a3a-2127-422b-91ae-364da2661108https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA43730
af854a3a-2127-422b-91ae-364da2661108https://support.f5.com/csp/article/K57211290?utm_source=f5support&amp%3Butm_medium=RSS
af854a3a-2127-422b-91ae-364da2661108https://tools.ietf.org/html/draft-ietf-6man-deprecate-atomfrag-generation-08Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://tools.ietf.org/html/rfc8021Third Party Advisory
Impacted products
Vendor Product Version
n/a n/a Version: n/a
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         id: "CVE-2016-10142",
         lastModified: "2024-11-21T02:43:24.000",
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That is, employing fragmentation where not actually needed allows for fragmentation-based attack vectors to be employed, unnecessarily. We note that, unfortunately, even nodes that already implement [RFC6946] can be subject to DoS attacks as a result of the generation of IPv6 atomic fragments. Let us assume that Host A is communicating with Host B and that, as a result of the widespread dropping of IPv6 packets that contain extension headers (including fragmentation) [RFC7872], some intermediate node filters fragments between Host B and Host A. If an attacker sends a forged ICMPv6 PTB error message to Host B, reporting an MTU smaller than 1280, this will trigger the generation of IPv6 atomic fragments from that moment on (as required by [RFC2460]). When Host B starts sending IPv6 atomic fragments (in response to the received ICMPv6 PTB error message), these packets will be dropped, since we previously noted that IPv6 packets with extension headers were being dropped between Host B and Host A. Thus, this situation will result in a DoS scenario. Another possible scenario is that in which two BGP peers are employing IPv6 transport and they implement Access Control Lists (ACLs) to drop IPv6 fragments (to avoid control-plane attacks). If the aforementioned BGP peers drop IPv6 fragments but still honor received ICMPv6 PTB error messages, an attacker could easily attack the corresponding peering session by simply sending an ICMPv6 PTB message with a reported MTU smaller than 1280 bytes. Once the attack packet has been sent, the aforementioned routers will themselves be the ones dropping their own traffic.\"},{\"lang\":\"es\",\"value\":\"Se descubrió un problema en la especificación de protocolo IPv6, relacionado con los mensajes ICMP Packet Too Big (PTB). (El alcance de esta CVE afecta a todas las implementaciones IPv6 de todos los vendedores.) Las implicaciones de seguridad de fragmentación IP se han discutido extensamente en [RFC6274] y [RFC7739]. Un atacante puede aprovechar la generación de fragmentos atómicos IPv6 para desencadenar el uso de fragmentación en un flujo IPv6 arbitrariamente (en escenarios en los que no es necesaria la fragmentación real de paquetes) y puede posteriormente realizar cualquier tipo de ataque basado en fragmentación contra nodos IPv6 heredados que no implementan [RFC6946]. Es decir, empleando la fragmentación donde no se necesita realmente permite emplear vectores de ataque basados en fragmentación, innecesariamente. Observamos que, desafortunadamente, incluso los nodos que ya implementan [RFC6946] pueden estar sujetos a ataques DoS como resultado de la generación de fragmentos atómicos IPv6. Vamos a asumir que el Host A se está comunicando con el Host B y que, como resultado de la caída generalizada de paquetes IPv6 que contienen cabeceras de extensión (incluyendo la fragmentación) [RFC7872], algunos nodos intermedios filtran fragmentos entre Host B y Host A. Si un atacante envía un mensaje de error falsificado ICMPv6 PTB al Host B, comunicando una MTU menor que 1280, esto desencadena la generación de fragmentos atómicos IPv6 a partir de ese momento (como es requerido por [RFC2460]). Cuando el Host B comienza a enviar fragmentos atómicos IPv6 (en respuesta al mensaje de error ICMPv6 PTB recibido), este paquete será perdido, ya que se anotó anteriormente que los paquetes IPv6 con los encabezados de la extensión estaban siendo caídos entre el Host B y el Host A. Por tanto, esta situación resultará en un escenario DoS. Otro posible escenario es aquel en el que dos pares BGP están empleando transporte IPv6 e implementan Access Control List (ACLs) para perder fragmentos IPv6 (para evitar ataques de plano de control). Si los pares BGP mencionados borran fragmentos IPv6 pero aún así cumplen con los mensajes de error ICMPv6 PTB recibidos, un atacante podría atacar fácilmente hurgando en la sesión correspondiente enviando simplemente un mensaje ICMPv6 PTB con una MTU reportada menor de 1280 bytes. Una vez que el paquete de ataque ha sido enviado, los routers citados serán ellos mismos los que caeran por su propio tráfico.\"}],\"metrics\":{\"cvssMetricV30\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.0\",\"vectorString\":\"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H\",\"baseScore\":8.6,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":4.0}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:N/AC:L/Au:N/C:N/I:N/A:P\",\"baseScore\":5.0,\"accessVector\":\"NETWORK\",\"accessComplexity\":\"LOW\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"PARTIAL\"},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":10.0,\"impactScore\":2.9,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":false}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-17\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:ietf:ipv6:-:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"9143AE03-F25A-4C4A-9037-DFBC9B4F5FB8\"}]}]}],\"references\":[{\"url\":\"http://rhn.redhat.com/errata/RHSA-2017-0817.html\",\"source\":\"cve@mitre.org\"},{\"url\":\"http://www.securityfocus.com/bid/95797\",\"source\":\"cve@mitre.org\"},{\"url\":\"http://www.securitytracker.com/id/1038256\",\"source\":\"cve@mitre.org\"},{\"url\":\"https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA43730\",\"source\":\"cve@mitre.org\"},{\"url\":\"https://support.f5.com/csp/article/K57211290?utm_source=f5support&amp%3Butm_medium=RSS\",\"source\":\"cve@mitre.org\"},{\"url\":\"https://tools.ietf.org/html/draft-ietf-6man-deprecate-atomfrag-generation-08\",\"source\":\"cve@mitre.org\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://tools.ietf.org/html/rfc8021\",\"source\":\"cve@mitre.org\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"http://rhn.redhat.com/errata/RHSA-2017-0817.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"http://www.securityfocus.com/bid/95797\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"http://www.securitytracker.com/id/1038256\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA43730\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://support.f5.com/csp/article/K57211290?utm_source=f5support&amp%3Butm_medium=RSS\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://tools.ietf.org/html/draft-ietf-6man-deprecate-atomfrag-generation-08\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://tools.ietf.org/html/rfc8021\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]}]}}",
   },
}


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