Home/CVE/PHPMailer before 6.5.0 on Windows allows remote code execution if lang_path is untrusted data and has a UNC pathname.
CVE

CVE-2021-34551

PHPMailer before 6.5.0 on Windows allows remote code execution if lang_path is untrusted data and has a UNC pathname.

PHPMailer before 6.5.0 on Windows allows remote code execution if lang_path is untrusted data and has a UNC pathname.

HIGH · CVSS 8.1 EPSS 0.02108
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules7 YARA rules0
⬡

Weakness Classification

CWE-434Unrestricted Upload of File with Dangerous Type
▤

Affected Products & Versions

2
phpmailer project phpmailer< 6.5.0
fedoraproject fedoraall versions
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Packagist phpmailer/phpmailer HIGH fixed in 6.5.0
◈

Sigma Hunt Rules

7
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
productcriticalHackTool - Windows Credential Editor (WCE) Execution
productcriticalWindows Credential Editor Registry
producthighOpenCanary - MSSQL Login Attempt Via Windows Authentication
producthighWindows LAPS Credential Dump From Entra ID
producthighTamper Windows Defender - PSClassic
producthighTamper Windows Defender Remove-MpPreference - ScriptBlockLogging
▣

Scoring & Timeline

8.1
HIGH · CVSS v3.1 · cve@mitre.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD16 Jun 2021 · 06:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
🔗

References & Sources

3
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/PHPMailer/PHPMailer/blob/master/SECURITY.mdIssue TrackingThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3YRMWGA4VTMXFB22KICMB7YMFZNFV3EJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FJYSOFCUBS67J3TKR74SD3C454N7VTYM/
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