Script `ssl-ccs-injection`

Script types: portrule
Categories: vuln, safe
Download: https://svn.nmap.org/nmap/scripts/ssl-ccs-injection.nse

Script Summary

Detects whether a server is vulnerable to the SSL/TLS "CCS Injection" vulnerability (CVE-2014-0224), first discovered by Masashi Kikuchi. The script is based on the ccsinjection.c code authored by Ramon de C Valle (https://gist.github.com/rcvalle/71f4b027d61a78c42607)

In order to exploit the vulnerablity, a MITM attacker would effectively do the following:

o Wait for a new TLS connection, followed by the ClientHello ServerHello handshake messages.

o Issue a CCS packet in both the directions, which causes the OpenSSL code to use a zero length pre master secret key. The packet is sent to both ends of the connection. Session Keys are derived using a zero length pre master secret key, and future session keys also share this weakness.

o Renegotiate the handshake parameters.

o The attacker is now able to decrypt or even modify the packets in transit.

The script works by sending a 'ChangeCipherSpec' message out of order and checking whether the server returns an 'UNEXPECTED_MESSAGE' alert record or not. Since a non-patched server would simply accept this message, the CCS packet is sent twice, in order to force an alert from the server. If the alert type is different than 'UNEXPECTED_MESSAGE', we can conclude the server is vulnerable.

Script Arguments

tls.servername: See the documentation for the tls library.
smbdomain, smbhash, smbnoguest, smbpassword, smbtype, smbusername: See the documentation for the smbauth library.
mssql.domain, mssql.instance-all, mssql.instance-name, mssql.instance-port, mssql.password, mssql.protocol, mssql.scanned-ports-only, mssql.timeout, mssql.username: See the documentation for the mssql library.
smtp.domain: See the documentation for the smtp library.
randomseed, smbbasic, smbport, smbsign: See the documentation for the smb library.
vulns.short, vulns.showall: See the documentation for the vulns library.

Example Usage

nmap -p 443 --script ssl-ccs-injection <target>

Script Output

PORT    STATE SERVICE
443/tcp open  https
| ssl-ccs-injection:
|   VULNERABLE:
|   SSL/TLS MITM vulnerability (CCS Injection)
|     State: VULNERABLE
|     Risk factor: High
|     Description:
|       OpenSSL before 0.9.8za, 1.0.0 before 1.0.0m, and 1.0.1 before
|       1.0.1h does not properly restrict processing of ChangeCipherSpec
|       messages, which allows man-in-the-middle attackers to trigger use
|       of a zero-length master key in certain OpenSSL-to-OpenSSL
|       communications, and consequently hijack sessions or obtain
|       sensitive information, via a crafted TLS handshake, aka the
|       "CCS Injection" vulnerability.
|
|     References:
|       https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-0224
|       http://www.cvedetails.com/cve/2014-0224
|_      http://www.openssl.org/news/secadv_20140605.txt

Requires

Author:

Claudiu Perta <claudiu.perta@gmail.com>