CVE-2021-22570 | Nullptr Dereference in Protobuf

Nullptr dereference when a null char is present in a proto symbol. The symbol is parsed incorrectly, leading to an unchecked call into the proto file's name during generation of the resulting error message. Since the symbol is incorrectly parsed, the file is nullptr. We recommend upgrading to version 3.15.0 or greater.

Published: 2022-01-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-22570 is rated Low Risk (37.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.14%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-22570

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-27 0.15% 0.14% -0.01%
2 2026-05-22 0.14% 0.15% +0.01%
3 2026-03-11 0.14%

Full EPSS history (28 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-22570

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/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:L)
A normal user session is enough; they don’t have to be admin.
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.
2.8 3.6 [email protected]
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/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:L)
A normal user session is enough; they don’t have to be admin.
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.
1.8 3.6 [email protected]
2.1 2.0 LOW
AV:L/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
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.
3.9 2.9 [email protected]

Weakness enumeration for CVE-2021-22570

GitHub Security Advisory for CVE-2021-22570

GHSA-77rm-9x9h-xj3g · Severity: high · Ecosystem: nuget — Withdrawn Advisory: NULL Pointer Dereference in Protocol Buffers

OS Trackers for CVE-2021-22570

vendor priority summary link
alpine high CVE-2021-22570: 1 source package rows (protobuf); 1 state rows across 1 repos (3.12-main); fixed 0, open 1. https://security.alpinelinux.org/vuln/CVE-2021-22570
debian not yet assigned CVE-2021-22570 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-2021-22570
redhat medium https://access.redhat.com/security/cve/CVE-2021-22570
suse medium CVE-2021-22570 severity moderate: SUSE including 324 source package names (0.21.0.1.8.13:libprotobuf-lite20-3.9.2-4.12.1, 0.23.0.3.2.201:libprotobuf-lite20-3.9.2-4.12.1, …), 513 product×package rows across 136 product lines (Container bci/bci-init, Container bci/golang, … (136 product lines)): Fixed 433, Known Affected 78, First Fixed 2. https://www.suse.com/security/cve/CVE-2021-22570/
ubuntu low CVE-2021-22570 low priority: Ubuntu including 1 source packages (protobuf), 9 status rows across 9 suites (bionic, focal, impish, jammy, kinetic, lunar, trusty, upstream, xenial): released 7, ignored 1, not-affected 1. https://ubuntu.com/security/CVE-2021-22570

Affected software / configurations for CVE-2021-22570

Vendor Product Version Raw CPE
google protobuf < 3.15.0 cpe:2.3:a:google:protobuf:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
fedoraproject fedora 36 cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*
oracle mysql <= 8.0.28 cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:*
netapp active_iq_unified_manager cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*
netapp active_iq_unified_manager cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:windows:*:*
netapp oncommand_insight cpe:2.3:a:netapp:oncommand_insight:-:*:*:*:*:*:*:*
netapp oncommand_workflow_automation cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:*
netapp snapcenter cpe:2.3:a:netapp:snapcenter:-:*:*:*:*:*:*:*

References for CVE-2021-22570

URL Tags
https://github.com/protocolbuffers/protobuf/releases/tag/v3.15.0 Release Notes Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/04/msg00019.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3DVUZPALAQ34TQP6KFNLM4IZS6B32XSA/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5PAGL5M2KGYPN3VEQCRJJE6NA7D5YG5X/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BTRGBRC5KGCA4SK5MUNLPYJRAGXMBIYY/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IFX6KPNOFHYD6L4XES5PCM3QNSKZBOTQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KQJB6ZPRLKV6WCMX2PRRRQBFAOXFBK6B/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MRWRAXAFR3JR7XCFWTHC2KALSZKWACCE/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NVTWVQRB5OCCTMKEQFY5MYED3DXDVSLP/
https://security.netapp.com/advisory/ntap-20220429-0005/ Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Third Party Advisory
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