CyberSecBulletin
CVE-2022-49395NVD status: Modified

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2022-49395 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 668ca34a428d6ffc0f99a1a6a9b661a288d4183b, ef1dc929a1e5fa1b2d842256db9fb8710d3be910, 3549ab4b962cf619e8c55484a0d870a34b3f845f 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.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 668ca34a428d6ffc0f99a1a6a9b661a288d4183b or ef1dc929a1e5fa1b2d842256db9fb8710d3be910 or 3549ab4b962cf619e8c55484a0d870a34b3f845f or 9caad70819aef3431abaf73ba5163b55b161aba0, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.9.318 or 4.14.283 or 4.19.247 or 5.4.198, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux858259cf7d1c443c836a2022b78cb281f0a9b95e up to, but not including, 668ca34a428d6ffc0f99a1a6a9b661a288d4183b; 858259cf7d1c443c836a2022b78cb281f0a9b95e up to, but not including, ef1dc929a1e5fa1b2d842256db9fb8710d3be910; 858259cf7d1c443c836a2022b78cb281f0a9b95e up to, but not including, 3549ab4b962cf619e8c55484a0d870a34b3f845f; 858259cf7d1c443c836a2022b78cb281f0a9b95e up to, but not including, 9caad70819aef3431abaf73ba5163b55b161aba0; 858259cf7d1c443c836a2022b78cb281f0a9b95e up to, but not including, cf0dabc37446c5ee538ae7b4c467ab0e53fa5463; 858259cf7d1c443c836a2022b78cb281f0a9b95e up to, but not including, 10995a382271254bd276627ec74136da4a23c4a6; 858259cf7d1c443c836a2022b78cb281f0a9b95e up to, but not including, 24ca648bf5f72ed8878cf09b5d4431935779681e; 858259cf7d1c443c836a2022b78cb281f0a9b95e up to, but not including, 91e5ba2af2d729d5126aefd5aa3eadc69b8426e5; and 2 more ranges668ca34a428d6ffc0f99a1a6a9b661a288d4183b, ef1dc929a1e5fa1b2d842256db9fb8710d3be910, 3549ab4b962cf619e8c55484a0d870a34b3f845f, 9caad70819aef3431abaf73ba5163b55b161aba0, cf0dabc37446c5ee538ae7b4c467ab0e53fa5463, 10995a382271254bd276627ec74136da4a23c4a6
LinuxLinux Kernel2.6.15 up to, but not including, 4.9.318; 4.10 up to, but not including, 4.14.283; 4.15 up to, but not including, 4.19.247; 4.20 up to, but not including, 5.4.198; 5.5 up to, but not including, 5.10.121; 5.11 up to, but not including, 5.15.46; 5.16 up to, but not including, 5.17.14; 5.18 up to, but not including, 5.18.34.9.318, 4.14.283, 4.19.247, 5.4.198, 5.10.121, 5.15.46

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 3.17.1HighNVD
CVSS 3.17.1HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: um: Fix out-of-bounds read in LDT setup syscall_stub_data() expects the data_count parameter to be the number of longs, not bytes. ================================================================== BUG: KASAN: stack-out-of-bounds in syscall_stub_data+0x70/0xe0 Read of size 128 at addr 000000006411f6f0 by task swapper/1 CPU: 0 PID: 1 Comm: swapper Not tainted 5.18.0+ #18 Call Trace: show_stack.cold+0x166/0x2a7 __dump_stack+0x3a/0x43 dump_stack_lvl+0x1f/0x27 print_report.cold+0xdb/0xf81 kasan_report+0x119/0x1f0 kasan_check_range+0x3a3/0x440 memcpy+0x52/0x140 syscall_stub_data+0x70/0xe0 write_ldt_entry+0xac/0x190 init_new_ldt+0x515/0x960 init_new_context+0x2c4/0x4d0 mm_init.constprop.0+0x5ed/0x760 mm_alloc+0x118/0x170 0x60033f48 do_one_initcall+0x1d7/0x860 0x60003e7b kernel_init+0x6e/0x3d4 new_thread_handler+0x1e7/0x2c0 The buggy address belongs to stack of task swapper/1 and is located at offset 64 in frame: init_new_ldt+0x0/0x960 This frame has 2 objects: [32, 40) 'addr' [64, 80) 'desc' ==================================================================

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. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

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