CyberSecBulletin
CVE-2022-21757NVD status: Modified

MT6833, MT6853, MT6877, MT6885, MT6889…: Improper Validation of Integrity Check Value

CVE-2022-21757 is a high-severity improper validation of integrity check value vulnerability in MT6833, MT6853, MT6877, MT6885, MT6889, MT6983, MT6985, MT8167S, MT8168, MT8175, MT8183, MT8185, MT8362A, MT8365, MT8385, MT8667, MT8675, MT8766, MT8768, MT8786, MT8788, MT8789, MT8797 from MediaTek, 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. Affected MT6833, MT6853, MT6877, MT6885, MT6889, MT6983, MT6985, MT8167S, MT8168, MT8175, MT8183, MT8185, MT8362A, MT8365, MT8385, MT8667, MT8675, MT8766, MT8768, MT8786, MT8788, MT8789, MT8797 versions: Android 11.0, 12.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.56% 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. Check which version of MT6833, MT6853, MT6877, MT6885, MT6889, MT6983, MT6985, MT8167S, MT8168, MT8175, MT8183, MT8185, MT8362A, MT8365, MT8385, MT8667, MT8675, MT8766, MT8768, MT8786, MT8788, MT8789, MT8797 you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on corp.mediatek.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

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
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

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

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighNVD
CVSS 2.07.8HighNVD

Official description

In WIFI Firmware, there is a possible system crash due to a missing count check. This could lead to remote denial of service with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS06468894; Issue ID: ALPS06468894.

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

The underlying weakness: Improper Validation of Integrity Check Value

The product does not validate or incorrectly validates the integrity check values or checksums of a message.

How developers prevent this class of flaw

  • The protocol specification describes the algorithm used for calculating the checksum. It is then a matter of implementing the calculation and verifying that the calculated checksum and the received checksum match.

More Improper Validation of Integrity Check Value vulnerabilities (CWE-354)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Improper Validation of Integrity Check Value vulnerabilities

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