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SMTP header injection


Email injection is a security weakness that allows a malicious attacker to exploit email-related features, such as email contact forms found on websites, in order to send harmful email content to unintended recipients.


  • Sending arbitrary email in a wide variety of attacks, such as spam, phishing, spear phishing.


Completely limit unsecured mail functions. Implement the use of specialized services or secure e-mail libraries. Validate incoming data and the escape of data that is not properly encrypted.


Authenticated attacker with access to the web service using the SMTP service from the Internet.

Expected Remediation Time

⌚ 120 minutes.


Default score using CVSS 3.1. It may change depending on the context of the src.


  • Attack vector: N
  • Attack complexity: L
  • Privileges required: L
  • User interaction: N
  • Scope: C
  • Confidentiality: N
  • Integrity: N
  • Availability: L


  • Exploit code madurity: P
  • Remediation level: U
  • Report confidence: C


  • Vector string: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:L/E:P/RL:U/RC:C
  • Score:
    • Base: 5.0
    • Temporal: 4.7
  • Severity:
    • Base: Medium
    • Temporal: Medium

Compliant code

Non compliant code



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