Linux: Out-of-bounds Read
CVE-2025-37785 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 14da7dbecb430e35b5889da8dae7bef33173b351, e47f472a664d70a3d104a6c2a035cdff55a719b4, b7531a4f99c3887439d778afaf418d1a01a5f01b 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 0.32% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 14da7dbecb430e35b5889da8dae7bef33173b351 or e47f472a664d70a3d104a6c2a035cdff55a719b4 or b7531a4f99c3887439d778afaf418d1a01a5f01b or 89503e5eae64637d0fa2218912b54660effe7d93, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.236 or 5.15.180 or 6.1.134 or 6.6.87, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | ac27a0ec112a089f1a5102bc8dffc79c8c815571 up to, but not including, 14da7dbecb430e35b5889da8dae7bef33173b351; ac27a0ec112a089f1a5102bc8dffc79c8c815571 up to, but not including, e47f472a664d70a3d104a6c2a035cdff55a719b4; ac27a0ec112a089f1a5102bc8dffc79c8c815571 up to, but not including, b7531a4f99c3887439d778afaf418d1a01a5f01b; ac27a0ec112a089f1a5102bc8dffc79c8c815571 up to, but not including, 89503e5eae64637d0fa2218912b54660effe7d93; ac27a0ec112a089f1a5102bc8dffc79c8c815571 up to, but not including, 52a5509ab19a5d3afe301165d9b5787bba34d842; ac27a0ec112a089f1a5102bc8dffc79c8c815571 up to, but not including, b47584c556444cf7acb66b26a62cbc348eb92b78; ac27a0ec112a089f1a5102bc8dffc79c8c815571 up to, but not including, ac28c5684c1cdab650a7e5065b19e91577d37a4b; ac27a0ec112a089f1a5102bc8dffc79c8c815571 up to, but not including, 53bc45da8d8da92ec07877f5922b130562eb4b00; and 2 more ranges | 14da7dbecb430e35b5889da8dae7bef33173b351, e47f472a664d70a3d104a6c2a035cdff55a719b4, b7531a4f99c3887439d778afaf418d1a01a5f01b, 89503e5eae64637d0fa2218912b54660effe7d93, 52a5509ab19a5d3afe301165d9b5787bba34d842, b47584c556444cf7acb66b26a62cbc348eb92b78 |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) | V3.1.6 and later; V3.1.7 and later | Not stated |
| Linux | Linux Kernel | 2.6.19 up to, but not including, 5.10.236; 5.11 up to, but not including, 5.15.180; 5.16 up to, but not including, 6.1.134; 6.2 up to, but not including, 6.6.87; 6.7 up to, but not including, 6.12.23; 6.13 up to, but not including, 6.13.11; 6.14 up to, but not including, 6.14.2 | 5.10.236, 5.15.180, 6.1.134, 6.6.87, 6.12.23, 6.13.11 |
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.1 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix OOB read when checking dotdot dir Mounting a corrupted filesystem with directory which contains '.' dir entry with rec_len == block size results in out-of-bounds read (later on, when the corrupted directory is removed). ext4_empty_dir() assumes every ext4 directory contains at least '.' and '..' as directory entries in the first data block. It first loads the '.' dir entry, performs sanity checks by calling ext4_check_dir_entry() and then uses its rec_len member to compute the location of '..' dir entry (in ext4_next_entry). It assumes the '..' dir entry fits into the same data block. If the rec_len of '.' is precisely one block (4KB), it slips through the sanity checks (it is considered the last directory entry in the data block) and leaves "struct ext4_dir_entry_2 *de" point exactly past the memory slot allocated to the data block. The following call to ext4_check_dir_entry() on new value of de then dereferences this pointer which results in out-of-bounds mem access. Fix this by extending __ext4_check_dir_entry() to check for '.' dir entries that reach the end of data block. Make sure to ignore the phony dir entries for checksum (by checking name_len for non-zero). Note: This is reported by KASAN as use-after-free in case another structure was recently freed from the slot past the bound, but it is really an OOB read. This issue was found by syzkaller tool. Call Trace: [ 38.594108] BUG: KASAN: slab-use-after-free in __ext4_check_dir_entry+0x67e/0x710 [ 38.594649] Read of size 2 at addr ffff88802b41a004 by task syz-executor/5375 [ 38.595158] [ 38.595288] CPU: 0 UID: 0 PID: 5375 Comm: syz-executor Not tainted 6.14.0-rc7 #1 [ 38.595298] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 38.595304] Call Trace: [ 38.595308] <TASK> [ 38.595311] dump_stack_lvl+0xa7/0xd0 [ 38.595325] print_address_description.constprop.0+0x2c/0x3f0 [ 38.595339] ? __ext4_check_dir_entry+0x67e/0x710 [ 38.595349] print_report+0xaa/0x250 [ 38.595359] ? __ext4_check_dir_entry+0x67e/0x710 [ 38.595368] ? kasan_addr_to_slab+0x9/0x90 [ 38.595378] kasan_report+0xab/0xe0 [ 38.595389] ? __ext4_check_dir_entry+0x67e/0x710 [ 38.595400] __ext4_check_dir_entry+0x67e/0x710 [ 38.595410] ext4_empty_dir+0x465/0x990 [ 38.595421] ? __pfx_ext4_empty_dir+0x10/0x10 [ 38.595432] ext4_rmdir.part.0+0x29a/0xd10 [ 38.595441] ? __dquot_initialize+0x2a7/0xbf0 [ 38.595455] ? __pfx_ext4_rmdir.part.0+0x10/0x10 [ 38.595464] ? __pfx___dquot_initialize+0x10/0x10 [ 38.595478] ? down_write+0xdb/0x140 [ 38.595487] ? __pfx_down_write+0x10/0x10 [ 38.595497] ext4_rmdir+0xee/0x140 [ 38.595506] vfs_rmdir+0x209/0x670 [ 38.595517] ? lookup_one_qstr_excl+0x3b/0x190 [ 38.595529] do_rmdir+0x363/0x3c0 [ 38.595537] ? __pfx_do_rmdir+0x10/0x10 [ 38.595544] ? strncpy_from_user+0x1ff/0x2e0 [ 38.595561] __x64_sys_unlinkat+0xf0/0x130 [ 38.595570] do_syscall_64+0x5b/0x180 [ 38.595583] entry_SYSCALL_64_after_hwframe+0x76/0x7e
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.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/52a5509ab19a5d3afe301165d9b5787bba34d842
- git.kernel.org/stable/c/53bc45da8d8da92ec07877f5922b130562eb4b00
- git.kernel.org/stable/c/89503e5eae64637d0fa2218912b54660effe7d93
- git.kernel.org/stable/c/ac28c5684c1cdab650a7e5065b19e91577d37a4b
- git.kernel.org/stable/c/b47584c556444cf7acb66b26a62cbc348eb92b78
- git.kernel.org/stable/c/b7531a4f99c3887439d778afaf418d1a01a5f01b
- git.kernel.org/stable/c/d5e206778e96e8667d3bde695ad372c296dc9353
- git.kernel.org/stable/c/e47f472a664d70a3d104a6c2a035cdff55a719b4
Other references
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.1 High severity
- 7.5 High severity
- 8.8 High severity
- 7.1 High severity
- 7.1 High severity
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