CVE-2021-1939

Service interruption via invalid preemption toggle validation

Published Sep 17, 2021 · Updated Aug 3, 2024

Null-pointer dereference in Qualcomm Snapdragon Graphics allows local users to interrupt device service by toggling preemption enablement. The proprietary Graphics component improperly validates state when preemption enablement changes and consequently dereferences a null pointer. Local access to an affected chipset's graphics interface is required; Qualcomm has not disclosed the specific function or whether interruption causes a crash or reboot.

CVSS severity8.4
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Null-pointer dereference in Qualcomm Snapdragon Graphics allows local users to interrupt device service by toggling preemption enablement. The proprietary Graphics component improperly validates state when preemption enablement changes and consequently dereferences a null pointer. Local access to an affected chipset's graphics interface is required; Qualcomm has not disclosed the specific function or whether interruption causes a crash or reboot.

The record

CVE
CVE-2021-1939
Published
Sep 17, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-476
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 17, 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 vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.4Qualcomm, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.9NIST NVDAV:L/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)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference

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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