MS14-066: Vulnerability in Schannel Could Allow Remote Code Execution (2992611)(WINSHOCK) The remote Windows host is affected by a remote code execution vulnerability due to
improper processing of packets by the SecureChannel (Schannel) security package. An
attacker can exploit this issue by sending specially crafted packets to a Windows server.
Note that this plugin sends a client Certificate TLS handshake message followed by a
CertificateVerify message. Some Windows hosts will close the connection upon
receiving a client certificate for which it did not ask for with a CertificateRequest
message. In this case, the plugin cannot proceed to detect the vulnerability as the
CertificateVerify message cannot be sent.
EXPLOIT:
The exploit for this vulnerability is a remote code execution that typically results in a
PEN TEST REPORT: EXAMPLE INSTITUTE
JANUARY 1, 2020
16
sales@purplesec.us
Denial of Service (DoS) Attack. Due to the nature of the testing, this exploit is out of
scope for the exercise.
Outsider Risk Rating:
Insider Risk Rating: EXTREME
Bottom Line:
Nearly all CLIENT’s internal networks hosts appear to be properly patched and up
-to-
date. Attack vectors are available to an adversary who targeted CLIENT. Considering
CLIENT’s lack of IT personnel or Security Engineer, an attacker could find success
through Social Engineering or Physical attack methods due to the lack of training and
resources found during this penetration testing.
Recommendations:
•
Disable SMB on all systems where it is not required for business purposes. The
service may be shut down via GPO on the domain, or through manual service
disabling on local admin accounts.
•
Disable spoolsvc.exe and other non-essential processes on Critical Security
Infrastructure such as the McAfee Security Server. Processes running increase
the attack surface of the systems. Disabling these services can help harden the
systems and create a smaller, more secure risk landscape.
•
Disable SSLv2 and SSLv3 on any system where legacy encryption is not
necessary. Most applications use better encryption built-in but use SSL as a
fallback option when needed for legacy support.
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PEN TEST REPORT: EXAMPLE INSTITUTE
JANUARY 1, 2020