Casa » Notícia » Linux e FreeBSD TCP Pilhas Revelado DoS Vulnerabilities

Linux e FreeBSD TCP Pilhas Revelado DoS Vulnerabilities

Um número de vulnerabilidades foram identificadas no FreeBSD e Linux pilhas TCP que potencialmente permitir remotamente causando uma negação de serviço ou causar o consumo de recursos excessivo durante o processamento de pacotes TCP especialmente criados.

Problems exist due to errors in the handler of the maximum data block size in the TCP packet (MSS, O tamanho máximo do segmento) and the mechanism for selective acknowledgment of TCP SACK. These vulnerabilities can pose a threat to a significant number of devices, including servers, Android gadgets, and embedded devices.

CVE-2019-11477 (SACK Panic) – this problem affects the Linux kernel, starting with version 2.6.29, and allows causing kernel crash by sending a series of SACK packets, which will cause an integer overflow in the handler. To prevent exploitation of the vulnerability, users are advised to disable SACK processing (write para /proc/sys/net/ipv4/tcp_sack) or block connections with a small MSS (the measure is effective only if you set sysctl net.ipv4.tcp_mtu_probing para and can lead to disruption some normal compounds with low MSS).

CVE-2019-11478 (SACK Slowness) – affects Linux kernel below 4.15 and leads to a failure of the SACK mechanism or excessive consumption of resources. It can be exploited by sending a series of specially crafted SACK packets.

CVE-2019-5599 (SACK Slowness) – manifested in FreeBSD 12 with the RACK packet loss detection mechanism. This problem allows fragmentation of a map of sent packets when processing a specially crafted SACK sequence within a single TCP connection. To prevent exploitation of the vulnerability, it is recommended to disable the RACK module.

CVE-2019-11479affects all versions of the Linux kernel. An attacker in the Linux kernel can cause responses to be split into several TCP segments, each of which includes only 8 bytes of data. This leads to a significant increase in traffic and Consumption of additional resources.

LER  Em mais de perseguido de plugins Jenkins são descobertas vulnerabilidades

Vulnerabilities are fixed in versions of the Linux kernel 4.4.182, 4.9.182, 4.14.127, 4.19.52 e 5.1.11. A patch for FreeBSD is also available. Kernel pack updates are released for Debian, RHEL, SUSE / openSUSE, ALT, Ubuntu, Fedora, and Arch Linux.

Nota:

Good system and application coding and configuration practices (limiting write buffers to the necessary level, monitoring connection memory consumption via SO_MEMINFO, and aggressively closing misbehaving connections) can help to limit the impact of attacks against these kinds of vulnerabilities.

Fonte: https://www.openwall.com

[Total: 0    Média: 0/5]

Sobre Trojan Killer

Carry Trojan Killer portátil em seu memory stick. Certifique-se que você é capaz de ajudar o seu PC resistir a quaisquer ameaças cibernéticas onde quer que vá.

Além disso, verifique

chaves mestras GandCrab

FBI lançado chaves mestras para descriptografar todas as versões Gandcrab

O FBI lançou chaves mestras para descriptografar arquivos afetados por versões ransomware Gandcrab 4, …

Emotet trojan

Índice Global Threat: Emotet rede de bots suspendeu as suas actividades

Verifique equipa Ponto Research (uma divisão da Check Point Software Technologies) publicou uma ameaça mundial …

Deixar uma resposta