CVE-2021-30340Network attack vector

Remote modem crash via malformed PDCCH configuration

Published Jun 14, 2022 · Updated Aug 3, 2024

Reachable assertion in Qualcomm Snapdragon modem firmware allows remote attackers to crash the modem via a crafted PDCCH configuration. In standalone 5G mode, the modem fails to validate a CORESET value in the physical downlink control channel configuration before an assertion evaluates it. No privileges or user interaction are required; the resulting crash interrupts cellular service without reported data disclosure or modification.

CVSS severity7.5
High
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in Qualcomm Snapdragon modem firmware allows remote attackers to crash the modem via a crafted PDCCH configuration. In standalone 5G mode, the modem fails to validate a CORESET value in the physical downlink control channel configuration before an assertion evaluates it. No privileges or user interaction are required; the resulting crash interrupts cellular service without reported data disclosure or modification.

The record

CVE
CVE-2021-30340
Published
Jun 14, 2022
Updated
Aug 3, 2024
Vendor
Qualcomm
Product
Snapdragon
Classifications
CWE-617, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 14, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=AR8035, QCA6390, QCA6391, QCA6426, QCA6436, QCA6574A, QCA6574AU, QCA6595AU, QCA6696, QCA8081, QCA8337, QCM6490, QCS6490, QCX315, SA515M, SD 8 Gen1 5G, SD480, SD690 5G, SD750G, SD765, SD765G, SD768G, SD778G, SD780G, SD865 5G, SD870, SD888 5G, SDX55, SDX55M, SDX65, SDXR2 5G, SM6375, SM7250P, SM7325P, WCD9341, WCD9360, WCD9370, WCD9375, WCD9380, WCD9385, WCN3988, WCN3991, WCN3998, WCN6740, WCN6750, WCN6850, WCN6851, WCN6855, WCN6856, WSA8810, WSA8815, WSA8830, WSA8835

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Qualcomm · Snapdragonversion=AR8035, QCA6390, QCA6391, QCA6426, QCA6436, QCA6574A, QCA6574AU, QCA6595AU, QCA6696, QCA8081, QCA8337, QCM6490, QCS6490, QCX315, SA515M, SD 8 Gen1 5G, SD480, SD690 5G, SD750G, SD765, SD765G, SD768G, SD778G, SD780G, SD865 5G, SD870, SD888 5G, SDX55, SDX55M, SDX65, SDXR2 5G, SM6375, SM7250P, SM7325P, WCD9341, WCD9360, WCD9370, WCD9375, WCD9380, WCD9385, WCN3988, WCN3991, WCN3998, WCN6740, WCN6750, WCN6850, WCN6851, WCN6855, WCN6856, WSA8810, WSA8815, WSA8830, WSA8835

Published CVSS scores

7.5QualcommCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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-617Reachable Assertion
T1499.004Application or System Exploitation

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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