ugh.book

Holes in the Armor 245 Superuser: The Superflaw All multiuser operating systems need privileged accounts. Virtually all multiuse ...

246 Security AT&T was so pleased with the SUID concept that it patented it. The intent was that SUID would simplify operatin ...

Holes in the Armor 247 * * ... */ There was just one problem: the original author of movemail had never suspected that the progr ...

248 Security Now, what’s wrong with this? Ping, it turns out, is a setuid root pro- gram, and now when I’m done with it I CAN’T ...

Holes in the Armor 249 The Problem with PATH Unix has to locate the executable image that corresponds to a given com- mand name. ...

250 Security run the newly created /tmp/.sh1 to read, delete, or run any of his files with- out the formality of learning his pa ...

Holes in the Armor 251 A trusted path is a fundamental requirement for computer security, yet it is theoretically impossible to ...

252 Security and, after cracking the system, makes it is relatively easy to create holes to allow future reentry. Cryptic Encryp ...

Holes in the Armor 253 Further, Bell Laboratories assumes no obligation to furnish any assis- tance of any kind whatsoever, or t ...

254 Security of-service attacks. Unix was created in a research environment in which it was more important to allow users to exp ...

Holes in the Armor 255 any per-user CPU time quotas. With a per-user process limit set at 50, those 50 processes from the attack ...

256 Security The Worms Crawl In In November 1988, an electronic parasite (a “worm”) disabled thousands of workstations and super ...

The Worms Crawl In 257 From: Klaus Brunnstein [email protected] To: [email protected] Subject: UNI ...

260 ...

13 The File System Sure It Corrupts Your Files, But Look How Fast It Is! Pretty daring of you to be storing important files on a ...

262 The File System What’s a File System? A file system is the part of a computer’s operating system that manages file storage o ...

What’s a File System? 263 system might actually be a symbolic link. Others didn’t.^1 Some programs worked as expected. Most didn ...

264 The File System for record-based operations: reading, writing, or locking a database record- by-record. (This might be one o ...

UFS: The Root of All Evil 265 UFS lives in a strange world where the computer’s hard disk is divided into three different parts: ...

266 The File System while the update is taking places. (Interrupting these sorts of operations can be like interrupting John McE ...