Linux Distros 未修補弱點：CVE-2022-49006
high Nessus Plugin ID 225798
語言:
概要
Linux/Unix 主機上安裝的一個或多個套件存有弱點，供應商表示將不會修補。說明
Linux/Unix 主機上安裝了一個或多個受到弱點影響的套件，且供應商未提供可用的修補程式。- 在 Linux 核心中，已解決下列弱點： tracing: Free buffers when a used dynamic event is removed After 65536 dynamic events have been added and removed, the type field of the event then uses the first type number that is available (not currently used by other events). A type number is the identifier of the binary blobs in the tracing ring buffer (known as events) to map them to logic that can parse the binary blob. The issue is that if a dynamic event (like a kprobe event) is traced and is in the ring buffer, and then that event is removed (because it is dynamic, which means it can be created and destroyed), if another dynamic event is created that has the same number that new event's logic on parsing the binary blob will be used. To show how this can be an issue, the following can crash the kernel: # cd /sys/kernel/tracing # for i in `seq 65536`; do echo 'p:kprobes/foo do_sys_openat2 $arg1:u32' > kprobe_events # done For every iteration of the above, the writing to the kprobe_events will remove the old event and create a new one (with the same format) and increase the type number to the next available on until the type number reaches over 65535 which is the max number for the 16 bit type. After it reaches that number, the logic to allocate a new number simply looks for the next available number.
When an dynamic event is removed, that number is then available to be reused by the next dynamic event created. That is, once the above reaches the max number, the number assigned to the event in that loop will remain the same. Now that means deleting one dynamic event and created another will reuse the previous events type number. This is where bad things can happen. After the above loop finishes, the kprobes/foo event which reads the do_sys_openat2 function call's first parameter as an integer. # echo 1 > kprobes/foo/enable # cat /etc/passwd > /dev/null # cat trace cat-2211 [005] .... 2007.849603: foo:
(do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849620: foo:
(do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849838: foo:
(do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849880: foo:
(do_sys_openat2+0x0/0x130) arg1=4294967196 # echo 0 > kprobes/foo/enable Now if we delete the kprobe and create a new one that reads a string: # echo 'p:kprobes/foo do_sys_openat2 +0($arg2):string' > kprobe_events And now we can the trace: # cat trace sendmail-1942 [002] ..... 530.136320: foo:
(do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.930817: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.930961: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.934278: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.934563: foo: (do_sys_openat2+0x0/0x240) arg1= ---truncated--- (CVE-2022-49006)
請注意，Nessus 依賴供應商報告的套件存在。
解決方案
目前尚未有已知的解決方案。Plugin 詳細資訊
嚴重性: High
ID: 225798
檔案名稱: unpatched_CVE_2022_49006.nasl
版本: 1.1
類型: local
代理程式: unix
系列: Misc.
已發布: 2025/3/5
已更新: 2025/3/5
支援的感應器: Nessus Agent, Nessus
風險資訊
VPR
風險因素: Medium
分數: 6.7
CVSS v2
風險因素: Medium
基本分數: 6.8
時間性分數: 5
媒介: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C
CVSS 評分資料來源: CVE-2022-49006
CVSS v3
風險因素: High
基本分數: 7.8
時間性分數: 6.8
媒介: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
時間媒介: CVSS:3.0/E:U/RL:O/RC:C
弱點資訊
必要的 KB 項目: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched
可輕鬆利用: No known exploits are available
弱點發布日期: 2023/1/18
參考資訊
CVE: CVE-2022-49006