CVE-2021-26109 Integer overflow in Fortinet FortiOS

What is CVE-2021-26109?

CVE-2021-26109 is a high-severity vulnerability in Fortinet Fortios, published on 8 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An integer overflow or wraparound vulnerability in the memory allocator of SSLVPN in FortiOS before 7.0.1 may allow an unauthenticated attacker to corrupt control data on the heap via specifically crafted requests to SSLVPN, resulting in potentially arbitrary code execution.

Weakness: CWE-190

Which versions are affected by CVE-2021-26109?

It affects 1 product.

Products include Fortinet Fortios.

How do I fix CVE-2021-26109?

No fix has been published for CVE-2021-26109 yet. Limit exposure of the affected software until one is available.

Is CVE-2021-26109 being exploited?

There is no known exploitation of CVE-2021-26109 in the wild and no public exploit code.

Other vulnerabilities in Fortinet Fortios

• CVE-2024-23113 Fortinet Multiple Products Format String Exploited Critical 9.8
• CVE-2022-40684 Fortinet Multiple Products Authentication Bypass Exploited Critical 9.8
• CVE-2024-55591 Fortinet FortiOS and FortiProxy Authentication Bypass Exploited Critical 9.6
• CVE-2024-21762 Fortinet FortiOS Out-of-Bound Write Exploited Critical 9.6
• CVE-2022-42475 Fortinet FortiOS Heap-Based Buffer Overflow Exploited Critical 9.3

All Fortinet Fortios vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-9h5m-38gw-j896.