Описание
The ping_unhash function in net/ipv4/ping.c in the Linux kernel before 4.0.3 does not initialize a certain list data structure during an unhash operation, which allows local users to gain privileges or cause a denial of service (use-after-free and system crash) by leveraging the ability to make a SOCK_DGRAM socket system call for the IPPROTO_ICMP or IPPROTO_ICMPV6 protocol, and then making a connect system call after a disconnect.
It was found that the Linux kernel's ping socket implementation did not properly handle socket unhashing during spurious disconnects, which could lead to a use-after-free flaw. On x86-64 architecture systems, a local user able to create ping sockets could use this flaw to crash the system. On non-x86-64 architecture systems, a local user able to create ping sockets could use this flaw to escalate their privileges on the system.
Отчет
This issue does not affect the Linux kernel as shipped with Red Hat Enterprise Linux 5. This issue does affect the Linux kernel as shipped with Red Hat Enterprise Linux 6, 7 and Red Hat Enterprise MRG 2. Future kernel updates for the respective releases will address this issue. Please note that on x86-64 architecture systems the impact is limited to local Denial of Service and that the ping sockets functionality is disabled by default (net.ipv4.ping_group_range sysctl is "10").
Меры по смягчению последствий
You can check whether ping socket functionality is enabled by examining the net.ipv4.ping_group_range sysctl value: ~]# sysctl net.ipv4.ping_group_range net.ipv4.ping_group_range = 10 "1 0" is the default value and disables the ping socket functionality even for root user. Any other value means that the ping socket functionality might be enabled for certain users on the system. To mitigate this vulnerability make sure that you either allow the functionality to trusted local users (groups) only or set the net.ipv4.ping_group_range sysctl to the default and disabled state: ~]# sysctl net.ipv4.ping_group_range="1 0" Please note that this might prevent some programs relying on this functionality from functioning properly.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 5 | kernel | Not affected | ||
| Red Hat Enterprise Linux Extended Update Support 6.2 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Fixed | RHSA-2015:1221 | 14.07.2015 |
| Red Hat Enterprise Linux 6.4 Advanced Update Support | kernel | Fixed | RHSA-2015:1643 | 18.08.2015 |
| Red Hat Enterprise Linux 6.5 Extended Update Support | kernel | Fixed | RHSA-2015:1583 | 11.08.2015 |
| Red Hat Enterprise Linux 7 | kernel-rt | Fixed | RHSA-2015:1565 | 05.08.2015 |
| Red Hat Enterprise Linux 7 | kernel | Fixed | RHSA-2015:1534 | 06.08.2015 |
| Red Hat Enterprise MRG 2 | kernel-rt | Fixed | RHSA-2015:1564 | 05.08.2015 |
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Дополнительная информация
Статус:
EPSS
6 Medium
CVSS2
Связанные уязвимости
The ping_unhash function in net/ipv4/ping.c in the Linux kernel before 4.0.3 does not initialize a certain list data structure during an unhash operation, which allows local users to gain privileges or cause a denial of service (use-after-free and system crash) by leveraging the ability to make a SOCK_DGRAM socket system call for the IPPROTO_ICMP or IPPROTO_ICMPV6 protocol, and then making a connect system call after a disconnect.
The ping_unhash function in net/ipv4/ping.c in the Linux kernel before 4.0.3 does not initialize a certain list data structure during an unhash operation, which allows local users to gain privileges or cause a denial of service (use-after-free and system crash) by leveraging the ability to make a SOCK_DGRAM socket system call for the IPPROTO_ICMP or IPPROTO_ICMPV6 protocol, and then making a connect system call after a disconnect.
The ping_unhash function in net/ipv4/ping.c in the Linux kernel before ...
The ping_unhash function in net/ipv4/ping.c in the Linux kernel before 4.0.3 does not initialize a certain list data structure during an unhash operation, which allows local users to gain privileges or cause a denial of service (use-after-free and system crash) by leveraging the ability to make a SOCK_DGRAM socket system call for the IPPROTO_ICMP or IPPROTO_ICMPV6 protocol, and then making a connect system call after a disconnect.
Уязвимость функции ping_unhash (net/ipv4/ping.c) ядра операционной системы Linux, позволяющая нарушителю повысить свои привилегии или вызвать отказ в обслуживании
EPSS
6 Medium
CVSS2