CVE-2023-42444 | phonenumber panics on parsing crafted RF3966 inputs

phonenumber is a library for parsing, formatting and validating international phone numbers. Prior to versions `0.3.3+8.13.9` and `0.2.5+8.11.3`, the phonenumber parsing code may panic due to a panic-guarded out-of-bounds access on the phonenumber string. In a typical deployment of `rust-phonenumber`, this may get triggered by feeding a maliciously crafted phonenumber over the network, specifically the string `.;phone-context=`. Versions `0.3.3+8.13.9` and `0.2.5+8.11.3` contain a patch for this issue. There are no known workarounds.

Published: 2023-09-19 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-42444 is rated Moderate Risk (59.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.69%). Mandatory action: 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-2023-42444

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 2026-06-14 0.55% 0.69% +0.14%
2 2025-11-21 0.66% 0.55% -0.11%
3 2025-11-18 0.66%

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-42444

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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 4.0 [email protected]
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]

Weakness enumeration for CVE-2023-42444

GitHub Security Advisory for CVE-2023-42444

GHSA-whhr-7f2w-qqj2 · Severity: high · Ecosystem: rust — phonenumber panics on parsing crafted RFC3966 inputs

Affected software / configurations for CVE-2023-42444

Vendor Product Version Raw CPE
whisperfish phonenumber < 0.2.5\+8.11.3 cpe:2.3:a:whisperfish:phonenumber:*:*:*:*:*:rust:*:*
whisperfish phonenumber >= 0.3.0\+8.12.9, < 0.3.3\+8.13.9 cpe:2.3:a:whisperfish:phonenumber:*:*:*:*:*:rust:*:*

References for CVE-2023-42444

cvelogic Threat Intelligence