CVE-2022-4203 | X.509 Name Constraints Read Buffer Overflow

A read buffer overrun can be triggered in X.509 certificate verification, specifically in name constraint checking. Note that this occurs after certificate chain signature verification and requires either a CA to have signed the malicious certificate or for the application to continue certificate verification despite failure to construct a path to a trusted issuer. The read buffer overrun might result in a crash which could lead to a denial of service attack. In theory it could also result in the disclosure of private memory contents (such as private keys, or sensitive plaintext) although we are not aware of any working exploit leading to memory contents disclosure as of the time of release of this advisory. In a TLS client, this can be triggered by connecting to a malicious server. In a TLS server, this can be triggered if the server requests client authentication and a malicious client connects.

Published: 2023-02-24 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-4203 is rated Moderate Risk (45.2/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.48%). Review affected assets and schedule remediation.

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-2022-4203

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 2026-06-15 0.51% 1.48% +0.97%
2 2026-05-18 0.57% 0.51% -0.06%
3 2026-04-19 — 0.57% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-4203

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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.
 1.2 3.6 [email protected]
4.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/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:H)
They need powerful rights—admin, root, or similar—before this pays off.
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.
 1.2 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2022-4203

GitHub Security Advisory for CVE-2022-4203

GHSA-w67w-mw4j-8qrv · Severity: critical · Ecosystem: rust — openssl-src contains Read Buffer Overflow in X.509 Name Constraint

OS Trackers for CVE-2022-4203

vendor priority summary link
alpine — CVE-2022-4203: 1 source package rows (openssl); 42 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 35. https://security.alpinelinux.org/vuln/CVE-2022-4203
debian unimportant CVE-2022-4203 unimportant priority: Debian including 1 source packages (openssl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-4203
gentoo normal CVE-2022-4203: 1 GLSA(s) (202402-08), 1 atom(s) (dev-libs/openssl); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-4203
redhat medium — https://access.redhat.com/security/cve/CVE-2022-4203
suse medium CVE-2022-4203 severity moderate: SUSE including 72 source package names (compat-openssl098, libopenssl-1_0_0-devel, …), 373 product×package rows across 46 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (46 product lines)): Known Not Affected 319, Fixed 54. https://www.suse.com/security/cve/CVE-2022-4203/
ubuntu medium CVE-2022-4203 medium priority: Ubuntu including 4 source packages (edk2, nodejs, openssl, openssl1.0), 34 status rows across 9 suites (bionic, focal, jammy, kinetic, lunar, mantic, trusty, upstream, xenial): not-affected 20, DNE 5, released 5, needs-triage 3, ignored 1. https://ubuntu.com/security/CVE-2022-4203

Affected software / configurations for CVE-2022-4203

Vendor Product Version Raw CPE
openssl openssl >= 3.0.0, < 3.0.8 cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*

References for CVE-2022-4203

cvelogic Threat Intelligence