The CVE-2025-3266 vulnerability in qinguoyi TinyWebServer (up to v1.0) allows remote attackers to trigger a stack-based buffer overflow via manipulated `name` or `password` arguments in the `/http/http_conn.cpp` component. This occurs due to insufficient bounds checking when processing user-supplied input, enabling an attacker to overwrite adjacent memory and potentially execute arbitrary code. The flaw is remotely exploitable without authentication, and public exploit PoCs exist. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L) reflects its network-based attack vector, low complexity, and impacts on confidentiality, integrity, and availability.
DailyCVE Form
Platform: TinyWebServer
Version: ≤1.0
Vulnerability: Buffer Overflow
Severity: Critical
Date: 04/07/2025
What Undercode Say:
Analytics:
- Attack Vector: Remote (HTTP requests)
- Exploitability: High (public PoC available)
- Mitigation Priority: Patch immediately
Exploit Command (PoC):
curl -X POST http://target:port/login -d "name=$(python3 -c 'print("A"1024)')&password=test"
Vulnerable Code Snippet (`http_conn.cpp`):
void http_conn::parse_form_data(char text) {
char name[bash], password[bash]; // Fixed-size buffers
sscanf(text, "name=%s&password=%s", name, password); // No length checks
}
Patch Code Fix:
void http_conn::parse_form_data(char text) {
char name[bash], password[bash];
snprintf(name, sizeof(name), "%.255s", strstr(text, "name=") + 5); // Bounds-checked
snprintf(password, sizeof(password), "%.255s", strstr(text, "password=") + 9);
}
Protection Commands:
1. Update TinyWebServer:
git clone https://patched_repo && make clean && make
2. WAF Rule (ModSecurity):
SecRule ARGS "@gt 255" "id:1000,deny,msg:'Buffer Overflow Attempt'"
3. Memory Protection (ASLR):
echo 2 | sudo tee /proc/sys/kernel/randomize_va_space
Detection (Log Analysis):
grep -E 'name=.{500,}|password=.{500,}' /var/log/tinywebserver.log
Mitigation:
- Disable HTTP form-based auth if unused.
- Deploy stack canaries (
-fstack-protectorGCC flag). - Monitor for anomalous payload lengths (>255 bytes).
References:
- VulDB: CVE-2025-3266
- NVD: NIST Entry
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-3266
Extra Source Hub:
Undercode
