Bugtraq mailing list archives
Re: /dev/tcp, and a LD_LIBRARY_PATH question.
From: rens () imsi com (Rens Troost)
Date: Sat, 03 Dec 1994 09:38:44 -0500
"hoodr" == hoodr <hoodr () hoodr slip netcom com> writes:
>> Second question: How can I write a program that keeps the >> LD_LIBRARY_PATH variable from being exploited? i.e. the SUN >> 'login' bug where LD_LIBRARY_PATH got exploited. I would ASSUME I >> could prevent this by doing something like: >> putenv("LD_LIBRARY_PATH"), but that just seems too simple to be a >> true fix. (If it's not complex, it's not right? :) hoodr> Don't assume that LD_LIBRAY_PATH is the only variable you hoodr> have to worry about. I was able to easily break "sudo" with hoodr> the LD_PRELOAD variable (we've since fixed it by supplying a hoodr> brand new environment, instead of re-using the old one). hoodr> A strings on /usr/lib/ld.so, show the following items which hoodr> are most likley environment variables: LD_LIBRARY_PATH hoodr> LD_TRACE_LOADED_OBJECTS LD_PROFILE LD_PRELOAD hoodr> LD_SYMBOLS_PUBLIC hoodr> Of course only LD_LIBRARY_PATH seems to be documented in the hoodr> man pages. Maybe someone from Sun can comment on what the hoodr> rest of these do (please?) >> From experimentation, the LD_PRELOAD variable should point to a hoodr> library (not a directory of libraries). That library will be hoodr> loaded before the standard library path (or LD_LIBRARY_PATH) hoodr> is searched. LD_PRELOAD allows you to override certain symbols from a library without having to provide teh entire library. Great for shipping quick bugfixes and economizing on space. -Rens
Current thread:
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. hoodr () hoodr slip netcom com (Dec 02)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Rens Troost (Dec 03)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Pat Myrto (Dec 03)
- <Possible follow-ups>
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. jim () Tadpole COM (Dec 02)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Ken Descoteaux (Dec 05)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Casper Dik (Dec 06)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Doug Hughes (Dec 05)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Bonfield James (Dec 06)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Todd C. Miller (Dec 06)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Bonfield James (Dec 06)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. hoodr () hoodr slip netcom com (Dec 05)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. James R. Ault (Dec 06)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Pat Myrto (Dec 07)
(Thread continues...)
- Re: /dev/tcp, and a LD_LIBRARY_PATH question. Rens Troost (Dec 03)