Martin Schwarzl (Graz University of Technology), Erik Kraft (Graz University of Technology), Moritz Lipp (Graz University of Technology), Daniel Gruss (Graz University of Technology)

Memory utilization can be reduced by merging identical memory blocks into copy-on-write mappings. Previous work showed that this so-called memory deduplication can be exploited in local attacks to break ASLR, spy on other programs, and determine the presence of data, i.e., website images. All these attacks exploit memory deduplication across security domains, which in turn was disabled. However, within a security domain or on an isolated system with no untrusted local access, memory deduplication is still not considered a security risk and was recently re-enabled on Windows by default.

In this paper, we present the first fully remote memory-deduplication attacks. Unlike previous attacks, our attacks require no local code execution. Consequently, we can disclose memory contents from a remote server merely by sending and timing HTTP/1 and HTTP/2 network requests. We demonstrate our attacks on deduplication both on Windows and Linux and attack widely used server software such as Memcached and InnoDB. Our side channel leaks up to 34.41B/h over the internet, making it faster than comparable remote memory-disclosure channels. We showcase our remote memory-deduplication attack in three case studies: First, we show that an attacker can disclose the presence of data in memory on a server running Memcached. We show that this information disclosure channel can also be used for fingerprinting and detect the correct libc version over the internet in 166.51s. Second, in combination with InnoDB, we present an information disclosure attack to leak MariaDB database records. Third, we demonstrate a fully remote KASLR break in less than 4 minutes allowing to derandomize the kernel image of a virtual machine over the Internet, i.e., 14 network hops away. We conclude that memory deduplication must also be considered a security risk if only applied within a single security domain.

View More Papers

Forensic Analysis of Configuration-based Attacks

Muhammad Adil Inam (University of Illinois at Urbana-Champaign), Wajih Ul Hassan (University of Illinois at Urbana-Champaign), Ali Ahad (University of Virginia), Adam Bates (University of Illinois at Urbana-Champaign), Rashid Tahir (University of Prince Mugrin), Tianyin Xu (University of Illinois at Urbana-Champaign), Fareed Zaffar (LUMS)

Read More

Hazard Integrated: Understanding Security Risks in App Extensions to...

Mingming Zha (Indiana University Bloomington), Jice Wang (National Computer Network Intrusion Protection Center, University of Chinese Academy of Sciences), Yuhong Nan (Sun Yat-sen University), Xiaofeng Wang (Indiana Unversity Bloomington), Yuqing Zhang (National Computer Network Intrusion Protection Center, University of Chinese Academy of Sciences), Zelin Yang (National Computer Network Intrusion Protection Center, University of Chinese Academy…

Read More

Dissecting American Fuzzy Lop – A FuzzBench Evaluation

Andrea Fioraldi (EURECOM), Alessandro Mantovani (EURECOM), Dominik Maier (TU Berlin), Davide Balzarotti (EURECOM)

Read More

GPSKey: GPS based Secret Key Establishment for Intra-Vehicle Environment

Edwin Yang (University of Oklahoma) and Song Fang (University of Oklahoma)

Read More