CVE-2021-1975Network attack vector

Remote memory corruption via malformed DNS response

Published Nov 12, 2021 · Updated Aug 3, 2024

Heap overflow in Qualcomm Snapdragon Data Modem allows remote attackers to corrupt memory by supplying a crafted DNS response. The Data Modem DNS-response parser accepts a domain value without an adequate length check, allowing it to exceed its heap allocation. No authentication or user interaction is required; the malformed response can corrupt modem memory across the listed Snapdragon chipset families.

CVSS severity9.8
Critical
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap overflow in Qualcomm Snapdragon Data Modem allows remote attackers to corrupt memory by supplying a crafted DNS response. The Data Modem DNS-response parser accepts a domain value without an adequate length check, allowing it to exceed its heap allocation. No authentication or user interaction is required; the malformed response can corrupt modem memory across the listed Snapdragon chipset families.

The record

CVE
CVE-2021-1975
Published
Nov 12, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 12, 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

10.0NIST NVDAV:N/AC:L/Au:N/C:C/I:C/A:C
9.8Qualcomm, Inc.CVSS:3.1/AV:N/AC:L/PR:N/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.

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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-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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