CVE-2021-30636Network attack vector

Memory corruption via allocator integer overflow

Published Jan 24, 2022 · Updated Aug 3, 2024

Integer overflow in MediaTek LinkIt SDK before 4.6.1 allows remote attackers to corrupt device memory through allocation requests. The pvPortCalloc and pvPortRealloc routines mishandle allocation-size arithmetic, allowing an oversized request to wrap before memory is allocated. No privileges or user interaction are required, but public records do not establish whether corruption yields a crash or code execution.

CVSS severity9.8
Critical
EPSS probability1.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in MediaTek LinkIt SDK before 4.6.1 allows remote attackers to corrupt device memory through allocation requests. The pvPortCalloc and pvPortRealloc routines mishandle allocation-size arithmetic, allowing an oversized request to wrap before memory is allocated. No privileges or user interaction are required, but public records do not establish whether corruption yields a crash or code execution.

The record

CVE
CVE-2021-30636
Published
Jan 24, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 24, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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