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CVE-2026-24017 is a high-severity vulnerability affecting Fortinet’s FortiWeb web application firewall. The issue stems from improper control of interaction frequency, classified under CWE-799. This flaw allows a remote, unauthenticated attacker to bypass the authentication rate-limiting mechanism. By sending specially crafted requests, an attacker can attempt to brute-force login credentials without being blocked or throttled by the security feature designed to prevent such attacks. The success of the attack hinges on the attacker’s available computational resources and the complexity of the target password. Essentially, the vulnerable rate-limiting control can be circumvented, enabling an unlimited number of login attempts. This significantly increases the risk of administrative account compromise through brute-force or dictionary attacks. Fortinet has released patches to address this vulnerability across all affected software versions.
Platform: Fortinet FortiWeb
Version: 7.0.0-8.0.2
Vulnerability :Rate-Limit Bypass
Severity: High
date: March 10, 2026
Prediction: Patch within 30 days
What Undercode Say:
Analytics:
CVE-2026-24017 exploits CWE-799, allowing unauthenticated remote attackers to bypass FortiWeb’s authentication rate limits via crafted requests. This brute-force amplification risk carries a CVSSv4 score of High, with vector AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N. The vulnerability affects versions 8.0.0-8.0.2, 7.6.0-7.6.5, 7.4.0-7.4.10, 7.2.0-7.2.11, and 7.0.0-7.0.11.
Bash Commands/Codes:
Check current FortiWeb version via CLI
get system status | grep "Version"
Simulate a rate-limit test (conceptual - use with caution)
for i in {1..1000}; do curl -X POST https://target.fortiweb/login -d "user=admin&password=$i" -H "X-Craft: $i" -s -o /dev/null -w "Request $i: HTTP %{http_code}\n"; sleep 0.1; done
Check for vulnerable rate-limiting by measuring response times
time seq 1 100 | xargs -I {} curl -s -o /dev/null -w "%{time_total}\n" https://target.fortiweb/login -d "user=admin&password=test" | awk '{sum+=$1} END {print "Average response: ", sum/NR}'
Exploit:
An unauthenticated attacker sends numerous login requests with varied passwords, bypassing the configured rate-limit. The vulnerability lies in the control’s failure to properly track interaction frequency. This allows the attacker to conduct a brute-force attack against the admin panel until valid credentials are found.
Protection:
Update FortiWeb to patched versions (8.0.3+, 7.6.6+, 7.4.11+, 7.2.12+, 7.0.12+). Implement additional brute-force protections like CAPTCHA and IP reputation lists. Monitor logs for excessive failed login attempts from single sources.
Impact:
Successful exploitation leads to administrative account compromise, granting full control over the web application firewall. This can result in data breaches, service disruption, and further network infiltration.
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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