CyberSecBulletin
CVE-2022-48747NVD status: Analyzed

Linux: Use of Uninitialized Resource

Published Updated By the CyberSecBulletin desk

CVE-2022-48747 is a high-severity use of uninitialized resource vulnerability in Linux, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 6cbf4c731d7812518cd857c2cfc3da9fd120f6ae, b63e120189fd92aff00096d11e2fc5253f60248b, 4633a79ff8bc82770486a063a08b55e5162521d8 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 0.92% chance of exploitation within 30 days, higher than 61% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 6cbf4c731d7812518cd857c2cfc3da9fd120f6ae or b63e120189fd92aff00096d11e2fc5253f60248b or 4633a79ff8bc82770486a063a08b55e5162521d8 or 941d5180c430ce5b0f7a3622ef9b76077bfa3d82, whichever matches your release line, or a later version.
  2. Update linux_kernel to 6cbf4c731d78 or b63e120189fd or 4633a79ff8bc or 941d5180c430, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux943cd69efac437d82a7aea0659fccbcc071730de up to, but not including, 6cbf4c731d7812518cd857c2cfc3da9fd120f6ae; 85a8ce62c2eabe28b9d76ca4eecf37922402df93 up to, but not including, b63e120189fd92aff00096d11e2fc5253f60248b; 85a8ce62c2eabe28b9d76ca4eecf37922402df93 up to, but not including, 4633a79ff8bc82770486a063a08b55e5162521d8; 85a8ce62c2eabe28b9d76ca4eecf37922402df93 up to, but not including, 941d5180c430ce5b0f7a3622ef9b76077bfa3d82; 85a8ce62c2eabe28b9d76ca4eecf37922402df93 up to, but not including, 3ee859e384d453d6ac68bfd5971f630d9fa46ad3; 5.4.9 up to, but not including, 5.4.176; 5.56cbf4c731d7812518cd857c2cfc3da9fd120f6ae, b63e120189fd92aff00096d11e2fc5253f60248b, 4633a79ff8bc82770486a063a08b55e5162521d8, 941d5180c430ce5b0f7a3622ef9b76077bfa3d82, 3ee859e384d453d6ac68bfd5971f630d9fa46ad3, 5.4.176
Linuxlinux_kernel1da177e4c3f4 up to, but not including, 6cbf4c731d78; 1da177e4c3f4 up to, but not including, b63e120189fd; 1da177e4c3f4 up to, but not including, 4633a79ff8bc; 1da177e4c3f4 up to, but not including, 941d5180c430; 1da177e4c3f4 up to, but not including, 3ee859e384d46cbf4c731d78, b63e120189fd, 4633a79ff8bc, 941d5180c430, 3ee859e384d4

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
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
NoneAvailability is not affected.

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

Official description

In the Linux kernel, the following vulnerability has been resolved: block: Fix wrong offset in bio_truncate() bio_truncate() clears the buffer outside of last block of bdev, however current bio_truncate() is using the wrong offset of page. So it can return the uninitialized data. This happened when both of truncated/corrupted FS and userspace (via bdev) are trying to read the last of bdev.

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

The underlying weakness: Use of Uninitialized Resource

The product uses or accesses a resource that has not been initialized.

How developers prevent this class of flaw

  • Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
  • Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
  • Avoid race conditions (CWE-362) during initialization routines.

More Use of Uninitialized Resource vulnerabilities (CWE-908)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use of Uninitialized Resource vulnerabilities

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