Linux: Out-of-bounds Read
CVE-2025-71093 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 4ccfa56f272241e8d8e2c38191fdbb03df489d80, 278b7cfe0d4da7502c7fd679b15032f014c92892, ad7a2a45e2417ac54089926b520924f8f0d91aea 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 0.29% 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 4ccfa56f272241e8d8e2c38191fdbb03df489d80 or 278b7cfe0d4da7502c7fd679b15032f014c92892 or ad7a2a45e2417ac54089926b520924f8f0d91aea or 2c4c0c09f9648ba766d399917d420d03e7b3e1f8, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.248 or 5.15.198 or 6.1.160 or 6.6.120, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 2037110c96d5f1dd71453fcd0d54e79be12a352b up to, but not including, 4ccfa56f272241e8d8e2c38191fdbb03df489d80; 2037110c96d5f1dd71453fcd0d54e79be12a352b up to, but not including, 278b7cfe0d4da7502c7fd679b15032f014c92892; 2037110c96d5f1dd71453fcd0d54e79be12a352b up to, but not including, ad7a2a45e2417ac54089926b520924f8f0d91aea; 2037110c96d5f1dd71453fcd0d54e79be12a352b up to, but not including, 2c4c0c09f9648ba766d399917d420d03e7b3e1f8; 2037110c96d5f1dd71453fcd0d54e79be12a352b up to, but not including, 26c8bebc2f25288c2bcac7bc0a7662279a0e817c; 2037110c96d5f1dd71453fcd0d54e79be12a352b up to, but not including, ee7c125fb3e8b04dd46510130b9fc92380e5d578; 2037110c96d5f1dd71453fcd0d54e79be12a352b up to, but not including, 9c72a5182ed92904d01057f208c390a303f00a0f; 3.18 | 4ccfa56f272241e8d8e2c38191fdbb03df489d80, 278b7cfe0d4da7502c7fd679b15032f014c92892, ad7a2a45e2417ac54089926b520924f8f0d91aea, 2c4c0c09f9648ba766d399917d420d03e7b3e1f8, 26c8bebc2f25288c2bcac7bc0a7662279a0e817c, ee7c125fb3e8b04dd46510130b9fc92380e5d578 |
| Linux | Linux Kernel | 3.18.1 up to, but not including, 5.10.248; 5.11 up to, but not including, 5.15.198; 5.16 up to, but not including, 6.1.160; 6.2 up to, but not including, 6.6.120; 6.7 up to, but not including, 6.12.64; 6.13 up to, but not including, 6.18.4; 3.18; 6.19 | 5.10.248, 5.15.198, 6.1.160, 6.6.120, 6.12.64, 6.18.4 |
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 | 9.1 | Critical | CNA |
| CVSS 3.1 | 7.1 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: e1000: fix OOB in e1000_tbi_should_accept() In e1000_tbi_should_accept() we read the last byte of the frame via 'data[length - 1]' to evaluate the TBI workaround. If the descriptor- reported length is zero or larger than the actual RX buffer size, this read goes out of bounds and can hit unrelated slab objects. The issue is observed from the NAPI receive path (e1000_clean_rx_irq): ================================================================== BUG: KASAN: slab-out-of-bounds in e1000_tbi_should_accept+0x610/0x790 Read of size 1 at addr ffff888014114e54 by task sshd/363 CPU: 0 PID: 363 Comm: sshd Not tainted 5.18.0-rc1 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x5a/0x74 print_address_description+0x7b/0x440 print_report+0x101/0x200 kasan_report+0xc1/0xf0 e1000_tbi_should_accept+0x610/0x790 e1000_clean_rx_irq+0xa8c/0x1110 e1000_clean+0xde2/0x3c10 __napi_poll+0x98/0x380 net_rx_action+0x491/0xa20 __do_softirq+0x2c9/0x61d do_softirq+0xd1/0x120 </IRQ> <TASK> __local_bh_enable_ip+0xfe/0x130 ip_finish_output2+0x7d5/0xb00 __ip_queue_xmit+0xe24/0x1ab0 __tcp_transmit_skb+0x1bcb/0x3340 tcp_write_xmit+0x175d/0x6bd0 __tcp_push_pending_frames+0x7b/0x280 tcp_sendmsg_locked+0x2e4f/0x32d0 tcp_sendmsg+0x24/0x40 sock_write_iter+0x322/0x430 vfs_write+0x56c/0xa60 ksys_write+0xd1/0x190 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f511b476b10 Code: 73 01 c3 48 8b 0d 88 d3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d f9 2b 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 8e 9b 01 00 48 89 04 24 RSP: 002b:00007ffc9211d4e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000004024 RCX: 00007f511b476b10 RDX: 0000000000004024 RSI: 0000559a9385962c RDI: 0000000000000003 RBP: 0000559a9383a400 R08: fffffffffffffff0 R09: 0000000000004f00 R10: 0000000000000070 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc9211d57f R14: 0000559a9347bde7 R15: 0000000000000003 </TASK> Allocated by task 1: __kasan_krealloc+0x131/0x1c0 krealloc+0x90/0xc0 add_sysfs_param+0xcb/0x8a0 kernel_add_sysfs_param+0x81/0xd4 param_sysfs_builtin+0x138/0x1a6 param_sysfs_init+0x57/0x5b do_one_initcall+0x104/0x250 do_initcall_level+0x102/0x132 do_initcalls+0x46/0x74 kernel_init_freeable+0x28f/0x393 kernel_init+0x14/0x1a0 ret_from_fork+0x22/0x30 The buggy address belongs to the object at ffff888014114000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1620 bytes to the right of 2048-byte region [ffff888014114000, ffff888014114800] The buggy address belongs to the physical page: page:ffffea0000504400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14110 head:ffffea0000504400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x100000000010200(slab|head|node=0|zone=1) raw: 0100000000010200 0000000000000000 dead000000000001 ffff888013442000 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected ================================================================== This happens because the TBI check unconditionally dereferences the last byte without validating the reported length first: u8 last_byte = *(data + length - 1); Fix by rejecting the frame early if the length is zero, or if it exceeds adapter->rx_buffer_len. This preserves the TBI workaround semantics for valid frames and prevents touching memory beyond the RX buffer.
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/26c8bebc2f25288c2bcac7bc0a7662279a0e817c
- git.kernel.org/stable/c/278b7cfe0d4da7502c7fd679b15032f014c92892
- git.kernel.org/stable/c/2c4c0c09f9648ba766d399917d420d03e7b3e1f8
- git.kernel.org/stable/c/4ccfa56f272241e8d8e2c38191fdbb03df489d80
- git.kernel.org/stable/c/9c72a5182ed92904d01057f208c390a303f00a0f
- git.kernel.org/stable/c/ad7a2a45e2417ac54089926b520924f8f0d91aea
- git.kernel.org/stable/c/ee7c125fb3e8b04dd46510130b9fc92380e5d578
Recent Out-of-bounds Read vulnerabilities
- 7.5 High severity
- 7.1 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.1 High severity
- 7.8 High severity
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