CVE-2021-35103

Memory corruption via unvalidated firmware timer count

Published Apr 1, 2022 · Updated Aug 4, 2024

An out-of-bounds write in Qualcomm Snapdragon WLAN firmware allows local users to corrupt memory while firmware timer values are synchronized. The WLAN timer-sync path fails to validate the number of timer values received from firmware before processing them in a bounded destination. The published record does not disclose the post-corruption behavior; exploitation requires low-privileged local access and no user interaction.

CVSS severity7.8
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds write in Qualcomm Snapdragon WLAN firmware allows local users to corrupt memory while firmware timer values are synchronized. The WLAN timer-sync path fails to validate the number of timer values received from firmware before processing them in a bounded destination. The published record does not disclose the post-corruption behavior; exploitation requires low-privileged local access and no user interaction.

The record

CVE
CVE-2021-35103
Published
Apr 1, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 1, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C
7.8Qualcomm, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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