Unauthenticated code execution via Content-Length integer overflow
Published Jan 2, 2023 · Updated Oct 21, 2025
Heap-based buffer overflow in affected Fortinet FortiOS and FortiProxy SSL-VPN releases allows remote attackers to execute code. The sslvpnd Content-Length parser truncates oversized values to 32 bits, allocates a small heap buffer, and copies the much larger POST body into it. No authentication or user interaction is required, but SSL-VPN must be enabled and reachable; successful exploitation runs attacker-controlled code on the appliance.
Summary
What happened
Heap-based buffer overflow in affected Fortinet FortiOS and FortiProxy SSL-VPN releases allows remote attackers to execute code. The sslvpnd Content-Length parser truncates oversized values to 32 bits, allocates a small heap buffer, and copies the much larger POST body into it. No authentication or user interaction is required, but SSL-VPN must be enabled and reachable; successful exploitation runs attacker-controlled code on the appliance.
The record
- CVE
- CVE-2022-42475
- Published
- Jan 2, 2023
- Updated
- Oct 21, 2025
- Vendor
- Fortinet
- Product
- FortiOS
- Classifications
- CWE-122, CWE-197, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 2, 2023CVE publishedPublication date reported by the CVE source.
- Oct 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.0.0 <=5.0.14
- Affected versionversion=5.2.0 <=5.2.15
- Affected versionversion=5.4.0 <=5.4.13
- Affected versionversion=5.6.0 <=5.6.14
- Affected versionversion=6.0.0 <=6.0.15
- Affected versionversion=6.2.0 <=6.2.11
- Affected versionversion=6.4.0 <=6.4.10
- Affected versionversion=7.0.0 <=7.0.8
- Affected versionversion=7.2.0 <=7.2.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- SCRT FortiOS SSL-VPN proof of conceptproof of concept · demonstrated
- Bishop Fox pre-authentication heap-overflow exploitfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- CISA Known Exploited Vulnerabilities entryknown exploited catalog
- Fortinet in-the-wild exploitation findingreported exploitation
Technologies
Your stack
See the directory against your own environment.
Your stack
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