CVE-2021-22569 [High] | Denial of Service in Google-Protobuf

An issue in protobuf-java allowed the interleaving of com.google.protobuf.UnknownFieldSet fields in such a way that would be processed out of order. A small malicious payload can occupy the parser for several minutes by creating large numbers of short-lived objects that cause frequent, repeated pauses. We recommend upgrading libraries beyond the vulnerable versions.

EDB-ID	Source	Kind	Published	Link
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Source

Kind

Published

Link

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Exploit-DB ↗

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-05-31	0.29%	0.47%	+0.18%
2	2025-11-21	0.25%	0.29%	+0.04%
3	2025-11-18	—	0.25%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-05-31

0.29%

0.47%

+0.18%

2025-11-21

0.25%

0.29%

+0.04%

2025-11-18

—

0.25%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	3.6	[email protected]
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. 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:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	3.6	[email protected]
4.3	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:N/I:N/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:P) Partial availability impact.	8.6	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

3.6

[email protected]

5.5

3.1

MEDIUM

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

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

3.6

[email protected]

4.3

2.0

MEDIUM

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

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:P): Partial availability impact.

8.6

2.9

[email protected]

OS Trackers for CVE-2021-22569

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2021-22569 not yet assigned priority: Debian including 1 source packages (protobuf), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2021-22569
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2021-22569
`suse`	medium	CVE-2021-22569 severity moderate: SUSE including 334 source package names (0.23.0.3.2.368:libprotobuf-lite20-3.9.2-150200.4.19.2, 0.58.0.17.143:libprotobuf-lite20-3.9.2-150200.4.19.2, …), 871 product×package rows across 140 product lines (Container bci/bci-init, Container bci/nodejs, … (140 product lines)): Fixed 735, Known Affected 110, Known Not Affected 24, First Fixed 2.	https://www.suse.com/security/cve/CVE-2021-22569/
`ubuntu`	low	CVE-2021-22569 low priority: Ubuntu including 1 source packages (protobuf), 9 status rows across 9 suites (bionic, focal, impish, jammy, kinetic, lunar, trusty, upstream, xenial): released 6, ignored 2, not-affected 1.	https://ubuntu.com/security/CVE-2021-22569

Affected software / configurations for CVE-2021-22569

Vendor	Product	Version	Raw CPE
google	google-protobuf	< 3.19.2	cpe:2.3:a:google:google-protobuf::::::ruby::*
google	protobuf-java	< 3.16.1	cpe:2.3:a:google:protobuf-java::::::::
google	protobuf-java	>= 3.18.0, < 3.18.2	cpe:2.3:a:google:protobuf-java::::::::
google	protobuf-java	>= 3.19.0, < 3.19.2	cpe:2.3:a:google:protobuf-java::::::::
google	protobuf-kotlin	< 3.18.2	cpe:2.3:a:google:protobuf-kotlin::::::::
google	protobuf-kotlin	>= 3.19.0, < 3.19.2	cpe:2.3:a:google:protobuf-kotlin::::::::
oracle	communications_cloud_native_core_console	1.9.0	cpe:2.3:a:oracle:communications_cloud_native_core_console:1.9.0:::::::*
oracle	communications_cloud_native_core_network_repository_function	1.15.0	cpe:2.3:a:oracle:communications_cloud_native_core_network_repository_function:1.15.0:::::::*
oracle	communications_cloud_native_core_network_repository_function	1.15.1	cpe:2.3:a:oracle:communications_cloud_native_core_network_repository_function:1.15.1:::::::*
oracle	communications_cloud_native_core_policy	1.15.0	cpe:2.3:a:oracle:communications_cloud_native_core_policy:1.15.0:::::::*
oracle	spatial_and_graph_mapviewer	19c	cpe:2.3:a:oracle:spatial_and_graph_mapviewer:19c:::::::*
oracle	spatial_and_graph_mapviewer	21c	cpe:2.3:a:oracle:spatial_and_graph_mapviewer:21c:::::::*

References for CVE-2021-22569

URL	Tags
http://www.openwall.com/lists/oss-security/2022/01/12/4	Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2022/01/12/7	Mailing List Third Party Advisory
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=39330	Exploit Issue Tracking Mailing List Vendor Advisory
https://cloud.google.com/support/bulletins#gcp-2022-001	Vendor Advisory
https://lists.debian.org/debian-lts-announce/2023/04/msg00019.html
https://www.oracle.com/security-alerts/cpuapr2022.html	Patch Third Party Advisory

URL

CVE-2021-22569 | Denial of Service of protobuf-java parsing procedure

Public exploit references (Exploit-DB) for CVE-2021-22569

Exploit prediction scoring system (EPSS) score for CVE-2021-22569

Common vulnerability scoring system (CVSS) metrics for CVE-2021-22569

Weakness enumeration for CVE-2021-22569

GitHub Security Advisory for CVE-2021-22569

OS Trackers for CVE-2021-22569

Affected software / configurations for CVE-2021-22569

References for CVE-2021-22569