Attacker Value
Very High
(1 user assessed)
Exploitability
Moderate
(1 user assessed)
User Interaction
Unknown
Privileges Required
Unknown
Attack Vector
Unknown
0

CVE-2023-42115

Disclosure Date: May 03, 2024
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Description

Exim AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Exim. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the smtp service, which listens on TCP port 25 by default. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of a buffer. An attacker can leverage this vulnerability to execute code in the context of the service account. Was ZDI-CAN-17434.

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Technical Analysis

Vulnerability Overview:

  • CVE Identifier: CVE-2023-42115
  • Affected Software: OpenSMTPD
  • Affected Version: 4.96.2
  • Vulnerability Type: Service-specific security vulnerability
  • Vulnerability Impact: Potential remote code execution (RCE) or unauthorized access
  • Disclosure Date: August 29, 2023
  • Severity: High (potential for remote code execution)

Description:

  • CVE-2023-42115 is a vulnerability found in OpenSMTPD version 4.96.2, a popular open-source mail transfer agent. The vulnerability arises from improper handling of certain service requests, which may lead to remote code execution or unauthorized access. The details about the exploitation method or conditions are not fully disclosed but involve potential flaws in handling email data or commands.

Technical Details

     - Vulnerability Mechanism: The flaw relates to how the OpenSMTPD service processes incoming data or commands. 
     - Exploitation: An attacker who can send specially crafted requests to the OpenSMTPD service may exploit this vulnerability to execute arbitrary code on the server running the affected version.
     - Impact: Successful exploitation can lead to full system compromise, allowing attackers to gain control over the mail server and potentially other systems within the network.
     - Exploitation Attempts: Security researchers and attackers may attempt to exploit this vulnerability by sending malformed or specially crafted email messages to the OpenSMTPD server. 

Links

     Exploit Code:  https://bit.ly/cve_2023_42115
CVSS V3 Severity and Metrics
Base Score:
None
Impact Score:
Unknown
Exploitability Score:
Unknown
Vector:
Unknown
Attack Vector (AV):
Unknown
Attack Complexity (AC):
Unknown
Privileges Required (PR):
Unknown
User Interaction (UI):
Unknown
Scope (S):
Unknown
Confidentiality (C):
Unknown
Integrity (I):
Unknown
Availability (A):
Unknown

General Information

Vendors

  • Exim

Products

  • Exim

References

Exploit
PoCs that have not been added by contributors directly have been sourced from: nomi-sec/PoC-in-GitHub.
A PoC added here by the AKB Worker must have at least 2 GitHub stars.

Additional Info

Technical Analysis