CVE-2021-42757 : Vulnerability Insights and Analysis
Discover the impact of CVE-2021-42757, a buffer overflow vulnerability in Fortinet FortiOS before 6.4.7 and FortiOS 7.0.0 through 7.0.2. Learn about the affected systems and versions and essential mitigation steps.
A buffer overflow vulnerability in Fortinet FortiOS before 6.4.7 and FortiOS 7.0.0 through 7.0.2 could allow an attacker to execute arbitrary code.
Understanding CVE-2021-42757
This CVE pertains to a buffer overflow issue in the TFTP client library of specific versions of Fortinet FortiOS.
What is CVE-2021-42757?
A buffer overflow in FortiOS versions before 6.4.7 and 7.0.0 through 7.0.2 could lead to arbitrary code execution by a locally authenticated attacker using crafted command line arguments.
The Impact of CVE-2021-42757
- CVSS Base Score: 6.3 (Medium)
- Attack Complexity: Low
- Attack Vector: Local
- Confidentiality Impact: High
- Integrity Impact: High
- Privileges Required: High
- Availability Impact: High
- Exploit Code Maturity: Proof of Concept
- User Interaction: None
- Vector String: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:U/RC:C
Technical Details of CVE-2021-42757
This section provides specific technical details related to the vulnerability.
Vulnerability Description
The vulnerability allows authenticated local attackers to execute arbitrary code via specially crafted command line arguments due to a buffer overflow in the TFTP client library.
Affected Systems and Versions
- Affected Product: Fortinet FortiOS
- Vendor: Fortinet
- Vulnerable Versions: FortiOS before 6.4.7, FortiOS 7.0.0 through 7.0.2
Exploitation Mechanism
The vulnerability can be exploited by an attacker who is authenticated locally by utilizing specifically manipulated command line arguments.
Mitigation and Prevention
It is crucial to take immediate and long-term security measures to address and prevent this vulnerability.
Immediate Steps to Take
- Patch FortiOS to version 6.4.7 or above to mitigate the vulnerability.
- Monitor network traffic and restrict TFTP services where possible.
Long-Term Security Practices
- Regularly update and patch all software and firmware in the network environment.
- Conduct security audits and penetration testing to identify and address potential vulnerabilities.
Patching and Updates
Ensure FortiOS is regularly updated to the latest patched version to avoid exposure to known vulnerabilities.