CVE-2021-32484Public exploitNetwork attack vector

Remote code execution via malformed EARFCN repetitions

Published Sep 9, 2021 · Updated Aug 3, 2024

Heap buffer overflow in MediaTek Modem LR12A and LR13 allows remote attackers to execute code via crafted 2G network messages. The 2G RRM EARFCN parser calculates a stream rewind in eight-bit arithmetic, misaligning repeated input and writing beyond its heap allocation. A device must be connected to a 2G cellular network; no privileges or user interaction are required, and exploitation runs code in the baseband runtime.

CVSS severity7.5
High
EPSS probability2.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in MediaTek Modem LR12A and LR13 allows remote attackers to execute code via crafted 2G network messages. The 2G RRM EARFCN parser calculates a stream rewind in eight-bit arithmetic, misaligning repeated input and writing beyond its heap allocation. A device must be connected to a 2G cellular network; no privileges or user interaction are required, and exploitation runs code in the baseband runtime.

The record

CVE
CVE-2021-32484
Published
Sep 9, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-122, CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 9, 2021CVE 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

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.8NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:C

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 exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

Public exploit references

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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