Fixing Races for Fun and Profit: How to Abuse atime
نویسندگان
چکیده
Dean and Hu proposed a probabilistic countermeasure to the classic access(2)/open(2) TOCTTOU race condition in privileged Unix programs [4]. In this paper, we describe an attack that succeeds with very high probability against their countermeasure. We then consider a stronger randomized variant of their defense and show that it, too, is broken. We conclude that access(2) must never be used in privileged Unix programs. The tools we develop can be used to attack other filesystem races, underscoring the importance of avoiding such races in secure software.
منابع مشابه
Fixing Races for Fun and Profit: How to Use access(2)
It is well known that it is insecure to use the access(2) system call in a setuid program to test for the ability of the program’s executor to access a file before opening said file. Although the access(2) call appears to have been designed exactly for this use, such use is vulnerable to a race condition. This race condition is a classic example of a time-of-check-to-time-of-use (TOCTTOU) probl...
متن کاملAntitrust Scrutiny of Price-Fixing Clauses in Patent Licenses
Patent licenses are frequently subjected to antitrust scrutiny, especially when they contain restrictions beyond simple fixed fees and royalties. Clauses that fix the price at which a product is sold have proven contentious, upheld by the courts in some circumstances and rejected in others. No agreement has yet emerged on how to reconcile court decisions and economic rationale. We study the eff...
متن کاملIdentifying Factors Affecting Fun in Workplace with Ethnography Approach
The purpose of this study is to identifying factors affecting Fun in Workplace in Army Physical Training Corps.The study type is developmental and mix method and to extract factors, ethnography methodology that is a qualitative method was used. To extract factors, ethnography methodology was used. Statistical population in this study consists of Army Physical Training Corps. In quantitative sec...
متن کاملJurisprudential study of the truth of damages based on non-profitability of the delay in payment for bank debtors and the feasibility of proving a guarantee for it
The issue of late payment of bank debtors and how to deal with it is one of the challenges of usury-free banking. After the the Islamic Revolution, many jurists considered the solution of the penalty for late payment to be haram (forbidden) as being ignorant usury. As a result, the banking system stopped receiving late payment penalties. Elimination of late payment penalties led to the abuse of...
متن کاملDouble spend races
We correct the double spend race analysis given in Nakamoto’s foundational Bitcoin article and give a closed-form formula for the probability of success of a double spend attack using the Regularized Incomplete Beta Function. We give the first proof of the exponential decay on the number of confirmations and find an asymptotic formula. Larger number of confirmations are necessary compared to th...
متن کامل