CVE-2021-1916 [Critical] | Out-of-bounds Write in Apq8009 Firmware

Possible buffer underflow due to lack of check for negative indices values when processing user provided input in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon IoT, Snapdragon Voice & Music, Snapdragon Wearables

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.33%	0.77%	+0.44%
2	2025-09-19	0.24%	0.33%	+0.09%
3	2025-03-30	—	0.24%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.33%

0.77%

+0.44%

2025-09-19

0.24%

0.33%

+0.09%

2025-03-30

—

0.24%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
10.0	2.0	HIGH	`AV:N/AC:L/Au:N/C:C/I:C/A:C` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:C) Complete confidentiality impact. Integrity impact (I:C) Complete integrity impact. Availability impact (A:C) Complete availability impact.	10.0	10.0	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

10.0

2.0

HIGH

AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:C): Complete confidentiality impact.
Integrity impact (I:C): Complete integrity impact.
Availability impact (A:C): Complete availability impact.

10.0

[email protected]

Affected software / configurations for CVE-2021-1916

Vendor	Product	Version	Raw CPE
qualcomm	apq8009_firmware	—	cpe:2.3:o:qualcomm:apq8009_firmware:-:::::::*
qualcomm	apq8009w_firmware	—	cpe:2.3:o:qualcomm:apq8009w_firmware:-:::::::*
qualcomm	apq8017_firmware	—	cpe:2.3:o:qualcomm:apq8017_firmware:-:::::::*
qualcomm	apq8037_firmware	—	cpe:2.3:o:qualcomm:apq8037_firmware:-:::::::*
qualcomm	apq8053_firmware	—	cpe:2.3:o:qualcomm:apq8053_firmware:-:::::::*
qualcomm	apq8084_firmware	—	cpe:2.3:o:qualcomm:apq8084_firmware:-:::::::*
qualcomm	apq8096au_firmware	—	cpe:2.3:o:qualcomm:apq8096au_firmware:-:::::::*
qualcomm	aqt1000_firmware	—	cpe:2.3:o:qualcomm:aqt1000_firmware:-:::::::*
qualcomm	ar6003_firmware	—	cpe:2.3:o:qualcomm:ar6003_firmware:-:::::::*
qualcomm	csr6030_firmware	—	cpe:2.3:o:qualcomm:csr6030_firmware:-:::::::*
qualcomm	csrb31024_firmware	—	cpe:2.3:o:qualcomm:csrb31024_firmware:-:::::::*
qualcomm	mdm8207_firmware	—	cpe:2.3:o:qualcomm:mdm8207_firmware:-:::::::*
qualcomm	mdm8215_firmware	—	cpe:2.3:o:qualcomm:mdm8215_firmware:-:::::::*
qualcomm	mdm8215m_firmware	—	cpe:2.3:o:qualcomm:mdm8215m_firmware:-:::::::*
qualcomm	mdm8615m_firmware	—	cpe:2.3:o:qualcomm:mdm8615m_firmware:-:::::::*
qualcomm	mdm9150_firmware	—	cpe:2.3:o:qualcomm:mdm9150_firmware:-:::::::*
qualcomm	mdm9205_firmware	—	cpe:2.3:o:qualcomm:mdm9205_firmware:-:::::::*
qualcomm	mdm9206_firmware	—	cpe:2.3:o:qualcomm:mdm9206_firmware:-:::::::*
qualcomm	mdm9207_firmware	—	cpe:2.3:o:qualcomm:mdm9207_firmware:-:::::::*
qualcomm	mdm9215_firmware	—	cpe:2.3:o:qualcomm:mdm9215_firmware:-:::::::*
qualcomm	mdm9230_firmware	—	cpe:2.3:o:qualcomm:mdm9230_firmware:-:::::::*
qualcomm	mdm9250_firmware	—	cpe:2.3:o:qualcomm:mdm9250_firmware:-:::::::*
qualcomm	mdm9310_firmware	—	cpe:2.3:o:qualcomm:mdm9310_firmware:-:::::::*
qualcomm	mdm9330_firmware	—	cpe:2.3:o:qualcomm:mdm9330_firmware:-:::::::*
qualcomm	mdm9607_firmware	—	cpe:2.3:o:qualcomm:mdm9607_firmware:-:::::::*
qualcomm	mdm9615_firmware	—	cpe:2.3:o:qualcomm:mdm9615_firmware:-:::::::*
qualcomm	mdm9615m_firmware	—	cpe:2.3:o:qualcomm:mdm9615m_firmware:-:::::::*
qualcomm	mdm9625_firmware	—	cpe:2.3:o:qualcomm:mdm9625_firmware:-:::::::*
qualcomm	mdm9628_firmware	—	cpe:2.3:o:qualcomm:mdm9628_firmware:-:::::::*
qualcomm	mdm9630_firmware	—	cpe:2.3:o:qualcomm:mdm9630_firmware:-:::::::*
qualcomm	mdm9635m_firmware	—	cpe:2.3:o:qualcomm:mdm9635m_firmware:-:::::::*
qualcomm	mdm9640_firmware	—	cpe:2.3:o:qualcomm:mdm9640_firmware:-:::::::*
qualcomm	mdm9645_firmware	—	cpe:2.3:o:qualcomm:mdm9645_firmware:-:::::::*
qualcomm	mdm9650_firmware	—	cpe:2.3:o:qualcomm:mdm9650_firmware:-:::::::*
qualcomm	mdm9655_firmware	—	cpe:2.3:o:qualcomm:mdm9655_firmware:-:::::::*
qualcomm	msm8108_firmware	—	cpe:2.3:o:qualcomm:msm8108_firmware:-:::::::*
qualcomm	msm8208_firmware	—	cpe:2.3:o:qualcomm:msm8208_firmware:-:::::::*
qualcomm	msm8209_firmware	—	cpe:2.3:o:qualcomm:msm8209_firmware:-:::::::*
qualcomm	msm8608_firmware	—	cpe:2.3:o:qualcomm:msm8608_firmware:-:::::::*
qualcomm	msm8909w_firmware	—	cpe:2.3:o:qualcomm:msm8909w_firmware:-:::::::*
qualcomm	msm8917_firmware	—	cpe:2.3:o:qualcomm:msm8917_firmware:-:::::::*
qualcomm	msm8920_firmware	—	cpe:2.3:o:qualcomm:msm8920_firmware:-:::::::*
qualcomm	msm8937_firmware	—	cpe:2.3:o:qualcomm:msm8937_firmware:-:::::::*
qualcomm	msm8940_firmware	—	cpe:2.3:o:qualcomm:msm8940_firmware:-:::::::*
qualcomm	msm8953_firmware	—	cpe:2.3:o:qualcomm:msm8953_firmware:-:::::::*
qualcomm	msm8976_firmware	—	cpe:2.3:o:qualcomm:msm8976_firmware:-:::::::*
qualcomm	msm8976sg_firmware	—	cpe:2.3:o:qualcomm:msm8976sg_firmware:-:::::::*
qualcomm	msm8996au_firmware	—	cpe:2.3:o:qualcomm:msm8996au_firmware:-:::::::*
qualcomm	qca1990_firmware	—	cpe:2.3:o:qualcomm:qca1990_firmware:-:::::::*
qualcomm	qca4004_firmware	—	cpe:2.3:o:qualcomm:qca4004_firmware:-:::::::*
qualcomm	qca6174_firmware	—	cpe:2.3:o:qualcomm:qca6174_firmware:-:::::::*
qualcomm	qca6174a_firmware	—	cpe:2.3:o:qualcomm:qca6174a_firmware:-:::::::*
qualcomm	qca6310_firmware	—	cpe:2.3:o:qualcomm:qca6310_firmware:-:::::::*
qualcomm	qca6320_firmware	—	cpe:2.3:o:qualcomm:qca6320_firmware:-:::::::*
qualcomm	qca6335_firmware	—	cpe:2.3:o:qualcomm:qca6335_firmware:-:::::::*
qualcomm	qca6390_firmware	—	cpe:2.3:o:qualcomm:qca6390_firmware:-:::::::*
qualcomm	qca6391_firmware	—	cpe:2.3:o:qualcomm:qca6391_firmware:-:::::::*
qualcomm	qca6420_firmware	—	cpe:2.3:o:qualcomm:qca6420_firmware:-:::::::*
qualcomm	qca6421_firmware	—	cpe:2.3:o:qualcomm:qca6421_firmware:-:::::::*
qualcomm	qca6426_firmware	—	cpe:2.3:o:qualcomm:qca6426_firmware:-:::::::*
qualcomm	qca6430_firmware	—	cpe:2.3:o:qualcomm:qca6430_firmware:-:::::::*
qualcomm	qca6431_firmware	—	cpe:2.3:o:qualcomm:qca6431_firmware:-:::::::*
qualcomm	qca6436_firmware	—	cpe:2.3:o:qualcomm:qca6436_firmware:-:::::::*
qualcomm	qca6564a_firmware	—	cpe:2.3:o:qualcomm:qca6564a_firmware:-:::::::*
qualcomm	qca6564au_firmware	—	cpe:2.3:o:qualcomm:qca6564au_firmware:-:::::::*
qualcomm	qca6574_firmware	—	cpe:2.3:o:qualcomm:qca6574_firmware:-:::::::*
qualcomm	qca6574a_firmware	—	cpe:2.3:o:qualcomm:qca6574a_firmware:-:::::::*
qualcomm	qca6574au_firmware	—	cpe:2.3:o:qualcomm:qca6574au_firmware:-:::::::*
qualcomm	qca6584_firmware	—	cpe:2.3:o:qualcomm:qca6584_firmware:-:::::::*
qualcomm	qca6584au_firmware	—	cpe:2.3:o:qualcomm:qca6584au_firmware:-:::::::*
qualcomm	qca6595au_firmware	—	cpe:2.3:o:qualcomm:qca6595au_firmware:-:::::::*
qualcomm	qca6694_firmware	—	cpe:2.3:o:qualcomm:qca6694_firmware:-:::::::*
qualcomm	qca6694au_firmware	—	cpe:2.3:o:qualcomm:qca6694au_firmware:-:::::::*
qualcomm	qca6696_firmware	—	cpe:2.3:o:qualcomm:qca6696_firmware:-:::::::*
qualcomm	qca9367_firmware	—	cpe:2.3:o:qualcomm:qca9367_firmware:-:::::::*
qualcomm	qca9377_firmware	—	cpe:2.3:o:qualcomm:qca9377_firmware:-:::::::*
qualcomm	qca9379_firmware	—	cpe:2.3:o:qualcomm:qca9379_firmware:-:::::::*
qualcomm	qcm4290_firmware	—	cpe:2.3:o:qualcomm:qcm4290_firmware:-:::::::*
qualcomm	qcm6125_firmware	—	cpe:2.3:o:qualcomm:qcm6125_firmware:-:::::::*
qualcomm	qcs410_firmware	—	cpe:2.3:o:qualcomm:qcs410_firmware:-:::::::*

References for CVE-2021-1916

URL	Tags
https://www.qualcomm.com/company/product-security/bulletins/august-2021-bulletin	Vendor Advisory

URL

CVE-2021-1916

Exploit prediction scoring system (EPSS) score for CVE-2021-1916

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1916

Weakness enumeration for CVE-2021-1916

Affected software / configurations for CVE-2021-1916

References for CVE-2021-1916