Linux Distros 未修補弱點：CVE-2021-47636
high Nessus Plugin ID 229856
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： ubifs: Fix read out-of-bounds in ubifs_wbuf_write_nolock() Function ubifs_wbuf_write_nolock() may access buf out of bounds in following process: ubifs_wbuf_write_nolock(): aligned_len = ALIGN(len, 8); // Assume len = 4089, aligned_len = 4096 if (aligned_len <= wbuf->avail) ... // Not satisfy if (wbuf->used) { ubifs_leb_write() // Fill some data in avail wbuf len -= wbuf->avail; // len is still not 8-bytes aligned aligned_len -= wbuf->avail; } n = aligned_len >> c->max_write_shift; if (n) { n <<= c->max_write_shift; err = ubifs_leb_write(c, wbuf->lnum, buf + written, wbuf->offs, n); // n > len, read out of bounds less than 8(n-len) bytes } , which can be catched by KASAN: ========================================================= BUG: KASAN: slab-out-of-bounds in ecc_sw_hamming_calculate+0x1dc/0x7d0 Read of size 4 at addr ffff888105594ff8 by task kworker/u8:4/128 Workqueue: writeback wb_workfn (flush-ubifs_0_0) Call Trace: kasan_report.cold+0x81/0x165 nand_write_page_swecc+0xa9/0x160 ubifs_leb_write+0xf2/0x1b0 [ubifs] ubifs_wbuf_write_nolock+0x421/0x12c0 [ubifs] write_head+0xdc/0x1c0 [ubifs] ubifs_jnl_write_inode+0x627/0x960 [ubifs] wb_workfn+0x8af/0xb80 Function ubifs_wbuf_write_nolock() accepts that parameter 'len' is not 8 bytes aligned, the 'len' represents the true length of buf (which is allocated in 'ubifs_jnl_xxx', eg. ubifs_jnl_write_inode), so ubifs_wbuf_write_nolock() must handle the length read from 'buf' carefully to write leb safely. Fetch a reproducer in [Link]. (CVE-2021-47636)
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: 229856
檔案名稱: unpatched_CVE_2021_47636.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: 6.0
CVSS v2
風險因素: Low
基本分數: 3.6
時間性分數: 2.7
媒介: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:P
CVSS 評分資料來源: CVE-2021-47636
CVSS v3
風險因素: High
基本分數: 7.1
時間性分數: 6.2
媒介: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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: 2025/2/26
參考資訊
CVE: CVE-2021-47636