csirt@kutim:~/threat-intel/cve/CVE-2021-47636

Katalog CVE

CVSS 7.1 · High EPSS 0,25%

Kerentanan Out-of-bounds Read pada linux kernel. Skor CVSS 3.1 7.1 (High) menurut NVD.

Deskripsi (NVD)

In the Linux kernel, the following vulnerability has been resolved: 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].

Rincian

Terbit di NVD
26 Februari 2025
Terakhir diubah
17 Juni 2026
Status NVD
Modified
CVSS 3.1
7.1 (High), sumber NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H · uraikan di kalkulator
Jenis kelemahan (CWE)
CWE-125: Out-of-bounds Read
EPSS (30 hari)
0,25% peluang dieksploitasi; lebih tinggi dari 15,6% CVE lain

Produk dan versi terdampak

VendorProdukVersi terdampak
linux linux kernel Versi 2.6.27 hingga sebelum 4.19.238
linux linux kernel Versi 4.20 hingga sebelum 5.4.189
linux linux kernel Versi 5.5 hingga sebelum 5.10.110
linux linux kernel Versi 5.11 hingga sebelum 5.15.33
linux linux kernel Versi 5.16 hingga sebelum 5.16.19
linux linux kernel Versi 5.17 hingga sebelum 5.17.2

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 5 Okt 2026, 20:10 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.