CyberSecBulletin
CVE-2025-38677NVD status: Modified

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2025-38677 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions ee4d13f5407cbdf1216cc258f45492075713889a, a650654365c57407413e9b1f6ff4d539bf2e99ca, 6b7784ea07e6aa044f74b39d6b5af5e28746fc81 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to ee4d13f5407cbdf1216cc258f45492075713889a or a650654365c57407413e9b1f6ff4d539bf2e99ca or 6b7784ea07e6aa044f74b39d6b5af5e28746fc81 or 901f62efd6e855f93d8b1175540f29f4dc45ba55, whichever matches your release line, or a later version.
  2. Update SIMATIC CN 4100 to V5.0 or a later version.
  3. Update Linux Kernel to 5.4.297 or 5.10.241 or 5.15.190 or 6.1.149, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux98e4da8ca301e062d79ae168c67e56f3c3de3ce4 up to, but not including, ee4d13f5407cbdf1216cc258f45492075713889a; 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 up to, but not including, a650654365c57407413e9b1f6ff4d539bf2e99ca; 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 up to, but not including, 6b7784ea07e6aa044f74b39d6b5af5e28746fc81; 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 up to, but not including, 901f62efd6e855f93d8b1175540f29f4dc45ba55; 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 up to, but not including, 92ef491b506a0f4dd971a3a76f86f2d8f5370180; 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 up to, but not including, 888aa660144bcb6ec07839da756ee46bfcf7fc53; 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 up to, but not including, f1d5093d9fe9f3c74c123741c88666cc853b79c5; 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 up to, but not including, 77de19b6867f2740cdcb6c9c7e50d522b47847a4; and 1 more rangesee4d13f5407cbdf1216cc258f45492075713889a, a650654365c57407413e9b1f6ff4d539bf2e99ca, 6b7784ea07e6aa044f74b39d6b5af5e28746fc81, 901f62efd6e855f93d8b1175540f29f4dc45ba55, 92ef491b506a0f4dd971a3a76f86f2d8f5370180, 888aa660144bcb6ec07839da756ee46bfcf7fc53
SiemensSIMATIC CN 4100before V5.0V5.0
LinuxLinux Kernel3.8 up to, but not including, 5.4.297; 5.5 up to, but not including, 5.10.241; 5.11 up to, but not including, 5.15.190; 5.16 up to, but not including, 6.1.149; 6.2 up to, but not including, 6.6.103; 6.7 up to, but not including, 6.12.44; 6.13 up to, but not including, 6.16.45.4.297, 5.10.241, 5.15.190, 6.1.149, 6.6.103, 6.12.44
DebianDebian Linux11.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.1HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid out-of-boundary access in dnode page As Jiaming Zhang reported: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x1c1/0x2a0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x17e/0x800 mm/kasan/report.c:480 kasan_report+0x147/0x180 mm/kasan/report.c:593 data_blkaddr fs/f2fs/f2fs.h:3053 [inline] f2fs_data_blkaddr fs/f2fs/f2fs.h:3058 [inline] f2fs_get_dnode_of_data+0x1a09/0x1c40 fs/f2fs/node.c:855 f2fs_reserve_block+0x53/0x310 fs/f2fs/data.c:1195 prepare_write_begin fs/f2fs/data.c:3395 [inline] f2fs_write_begin+0xf39/0x2190 fs/f2fs/data.c:3594 generic_perform_write+0x2c7/0x910 mm/filemap.c:4112 f2fs_buffered_write_iter fs/f2fs/file.c:4988 [inline] f2fs_file_write_iter+0x1ec8/0x2410 fs/f2fs/file.c:5216 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x546/0xa90 fs/read_write.c:686 ksys_write+0x149/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x3d0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The root cause is in the corrupted image, there is a dnode has the same node id w/ its inode, so during f2fs_get_dnode_of_data(), it tries to access block address in dnode at offset 934, however it parses the dnode as inode node, so that get_dnode_addr() returns 360, then it tries to access page address from 360 + 934 * 4 = 4096 w/ 4 bytes. To fix this issue, let's add sanity check for node id of all direct nodes during f2fs_get_dnode_of_data().

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

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