CVE-2021-30311

Heap corruption via unchecked NR5G buffer index

Published Jan 13, 2022 · Updated Aug 3, 2024

Heap overflow in Qualcomm Snapdragon NR5G modem firmware allows local users with low privileges to corrupt heap memory through a crafted index. The NR5G code fails to validate an index before it allocates and writes to a heap buffer, permitting an out-of-bounds write. Exploitation requires local low-privilege access; the resulting memory corruption can compromise confidentiality, integrity, and availability within the modem context.

CVSS severity7.8
High
EPSS probability0.16%
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 NR5G modem firmware allows local users with low privileges to corrupt heap memory through a crafted index. The NR5G code fails to validate an index before it allocates and writes to a heap buffer, permitting an out-of-bounds write. Exploitation requires local low-privilege access; the resulting memory corruption can compromise confidentiality, integrity, and availability within the modem context.

The record

CVE
CVE-2021-30311
Published
Jan 13, 2022
Updated
Aug 3, 2024
Vendor
Qualcomm
Product
Snapdragon
Classifications
CWE-129, CWE-20, CAPEC-100
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 13, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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 675, SD 8 Gen1 5G, SD460, SD480, SD662, SD665, SD675, SD678, SD690 5G, SD720G, SD730, SD750G, SD765, SD765G, SD768G, SD778G, SD780G, SD865 5G, SD870, SD888, SD888 5G, SDX55, SDX55M, SDX65, SDXR2 5G, SM6225, SM6250, SM6375, SM7250P, SM7315, SM7325P, WCD9341, WCD9360, WCD9370, WCD9375, WCD9380, WCD9385, WCN3950, WCN3980, WCN3988, WCN3991, WCN3998, WCN6740, WCN6750, WCN6850, WCN6851, WCN6855, WCN6856, WSA8810, WSA8815, WSA8830, WSA8835

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Qualcomm · Snapdragonversion=AR8035, QCA6390, QCA6391, QCA6426, QCA6436, QCA6574A, QCA6574AU, QCA6595AU, QCA6696, QCA8081, QCA8337, QCM6490, QCS6490, QCX315, SA515M, SD 675, SD 8 Gen1 5G, SD460, SD480, SD662, SD665, SD675, SD678, SD690 5G, SD720G, SD730, SD750G, SD765, SD765G, SD768G, SD778G, SD780G, SD865 5G, SD870, SD888, SD888 5G, SDX55, SDX55M, SDX65, SDXR2 5G, SM6225, SM6250, SM6375, SM7250P, SM7315, SM7325P, WCD9341, WCD9360, WCD9370, WCD9375, WCD9380, WCD9385, WCN3950, WCN3980, WCN3988, WCN3991, WCN3998, WCN6740, WCN6750, WCN6850, WCN6851, WCN6855, WCN6856, WSA8810, WSA8815, WSA8830, WSA8835

Published CVSS scores

7.8QualcommCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-129Improper Validation of Array Index
CWE-20Improper Input Validation
CAPEC-100Overflow Buffers

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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