简介
Linux/Unix 主机上安装的一个或多个程序包存在漏洞,但供应商表示不会修补此漏洞。
描述
Linux/Unix 主机中安装的一个或多个程序包受到一个漏洞影响,而供应商没有提供补丁程序。
- 在 Linux 内核中,已解决以下漏洞: net: ipv6: ensure we call ipv6_mc_down() at most once There are two reasons for addrconf_notify() to be called with NETDEV_DOWN:
either the network device is actually going down, or IPv6 was disabled on the interface. If either of them stays down while the other is toggled, we repeatedly call the code for NETDEV_DOWN, including ipv6_mc_down(), while never calling the corresponding ipv6_mc_up() in between. This will cause a new entry in idev->mc_tomb to be allocated for each multicast group the interface is subscribed to, which in turn leaks one struct ifmcaddr6 per nontrivial multicast group the interface is subscribed to. The following reproducer will leak at least $n objects: ip addr add ff2e::4242/32 dev eth0 autojoin sysctl -w net.ipv6.conf.eth0.disable_ipv6=1 for i in $(seq 1 $n); do ip link set up eth0; ip link set down eth0 done Joining groups with IPV6_ADD_MEMBERSHIP (unprivileged) or setting the sysctl net.ipv6.conf.eth0.forwarding to 1 (=> subscribing to ff02::2) can also be used to create a nontrivial idev->mc_list, which will the leak objects with the right up-down-sequence. Based on both sources for NETDEV_DOWN events the interface IPv6 state should be considered: - not ready if the network interface is not ready OR IPv6 is disabled for it - ready if the network interface is ready AND IPv6 is enabled for it The functions ipv6_mc_up() and ipv6_down() should only be run when this state changes. Implement this by remembering when the IPv6 state is ready, and only run ipv6_mc_down() if it actually changed from ready to not ready. The other direction (not ready -> ready) already works correctly, as: - the interface notification triggered codepath for NETDEV_UP / NETDEV_CHANGE returns early if ipv6 is disabled, and - the disable_ipv6=0 triggered codepath skips fully initializing the interface as long as addrconf_link_ready(dev) returns false - calling ipv6_mc_up() repeatedly does not leak anything (CVE-2022-48910)
请注意,Nessus 依赖供应商报告的程序包是否存在进行判断。
插件详情
文件名: unpatched_CVE_2022_48910.nasl
代理: unix
支持的传感器: Nessus Agent, Nessus
风险信息
矢量: CVSS2#AV:L/AC:L/Au:S/C:N/I:N/A:C
矢量: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
时间矢量: CVSS:3.0/E:U/RL:O/RC:C
漏洞信息
必需的 KB 项: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched
易利用性: No known exploits are available