Research

Situation A remote code execution (RCE) bug was found in log4j. CVE 2021-44228 has been assigned to it. The vulnerability lies in how log4j interprets Java Naming and Directory Interface (JNDI) URLs. JNDI lets an application look up a service. An attacker can craft a string that looks like “${jndi:proto://host/a}” where proto is ldap or rmi, and log4j will connect to the host to retrieve a, which would specify how to process the log entry. However, a can instead provide Java bytecode that log4j will execute. ...

In a recent demonstration of cyber and electronic warfare capabilities, I had the opportunity to enable access into a network by exploiting a computer remotely through a cell phone. In this blog post, I’ll document some of the challenges that were encountered and how they were overcome. Scenario The scenario for this demonstration was: an offensive cyber operations team wants to gain access into a targeted computer network which includes a wireless access point. The targeted network is firewalled and NAT’d, and social engineering techniques such as spear phishing have been unsuccessful. In order to gain access into the network, a human source is used to approach the facility that houses the network (think a residential building) and gains close enough proximity to sense the radio frequency (RF) emissions from the facility. ...

In a previous post I wrote about investigations that I performed on DNS over HTTPS (DoH). That research was performed as part of Cyber Security Research. During Security Tool Development, I expanded on that research by implementing a Python script which creates DNS wire format packets from a DoH packet capture. This post describes how that script was made and how it works. Updates to gen_doh.py In addition to the use of sslkeylog which was discussed in the previous post, I needed to update the client_protocol.py file. Line 45 of that file contains: ...

DNS Security As a plain-text protocol, DNS lacks Confidentiality, Integrity, and Availability (CIA) protections. An attacker who can observe DNS activity can see where the DNS request originated from, where responses came from, what the query and response were, or tamper with the response. DNS over HTTPS (DoH) effectively mitigates many of those weaknesses. Instead of being a plain-text protocol over UDP, DoH is an exchange of DNS queries and responses over a TLS encrypted connection, using the HTTP2 protocol to transmit messages. Because of this encryption, an attacker can neither observe nor tamper with DoH queries and responses. ...