CyberSecBulletin
CVE-2024-47727NVD status: Modified

Linux: Improper Check for Unusual or Exceptional Conditions

Published Updated By the CyberSecBulletin desk

CVE-2024-47727 is a high-severity improper check for unusual or exceptional conditions vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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 25703a3c980e21548774eea8c8a87a75c5c8f58c, 4c0c5dcb5471de5fc8f0a1c4980e5815339e1cee, 18ecd5b74682839e7cdafb7cd1ec106df7baa18c 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 0.25% 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 25703a3c980e21548774eea8c8a87a75c5c8f58c or 4c0c5dcb5471de5fc8f0a1c4980e5815339e1cee or 18ecd5b74682839e7cdafb7cd1ec106df7baa18c or bca2e29f7e26ce7c3522f8b324c0bd85612f68e3, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.113 or 6.6.54 or 6.10.13 or 6.11.2, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux31d58c4e557d46fa7f8557714250fb6f89c941ae up to, but not including, 25703a3c980e21548774eea8c8a87a75c5c8f58c; 31d58c4e557d46fa7f8557714250fb6f89c941ae up to, but not including, 4c0c5dcb5471de5fc8f0a1c4980e5815339e1cee; 31d58c4e557d46fa7f8557714250fb6f89c941ae up to, but not including, 18ecd5b74682839e7cdafb7cd1ec106df7baa18c; 31d58c4e557d46fa7f8557714250fb6f89c941ae up to, but not including, bca2e29f7e26ce7c3522f8b324c0bd85612f68e3; 31d58c4e557d46fa7f8557714250fb6f89c941ae up to, but not including, d4fc4d01471528da8a9797a065982e05090e1d81; 5.1925703a3c980e21548774eea8c8a87a75c5c8f58c, 4c0c5dcb5471de5fc8f0a1c4980e5815339e1cee, 18ecd5b74682839e7cdafb7cd1ec106df7baa18c, bca2e29f7e26ce7c3522f8b324c0bd85612f68e3, d4fc4d01471528da8a9797a065982e05090e1d81
LinuxLinux Kernel5.19 up to, but not including, 6.1.113; 6.2 up to, but not including, 6.6.54; 6.7 up to, but not including, 6.10.13; 6.11 up to, but not including, 6.11.26.1.113, 6.6.54, 6.10.13, 6.11.2

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
HighData or code can be modified at will.
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:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix "in-kernel MMIO" check TDX only supports kernel-initiated MMIO operations. The handle_mmio() function checks if the #VE exception occurred in the kernel and rejects the operation if it did not. However, userspace can deceive the kernel into performing MMIO on its behalf. For example, if userspace can point a syscall to an MMIO address, syscall does get_user() or put_user() on it, triggering MMIO #VE. The kernel will treat the #VE as in-kernel MMIO. Ensure that the target MMIO address is within the kernel before decoding instruction.

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

The underlying weakness: Improper Check for Unusual or Exceptional Conditions

The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Choose languages with features such as exception handling that force the programmer to anticipate unusual conditions that may generate exceptions. Custom exceptions may need to be developed to handle unusual business-logic conditions. Be careful not to pass sensitive exceptions back to the user (CWE-209, CWE-248).
  • Check the results of all functions that return a value and verify that the value is expected.
  • If using exception handling, catch and throw specific exceptions instead of overly-general exceptions (CWE-396, CWE-397). Catch and handle exceptions as locally as possible so that exceptions do not propagate too far up the call stack (CWE-705). Avoid unchecked or uncaught exceptions where feasible (CWE-248).

More Improper Check for Unusual or Exceptional Conditions vulnerabilities (CWE-754)

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 Improper Check for Unusual or Exceptional Conditions vulnerabilities

Spotted an error? Tell us.