Vulnerability Development mailing list archives
Possible syslogd DoS ?
From: Petr Baudis <pasky () pasky ji cz>
Date: Wed, 3 Oct 2001 20:09:58 +0200
Hello, I just recently came on a thought (thanks to Marek Jaros) of possible DoS of syslogd. It uses /dev/log for receiving log messages, which has mode 0666 on most linuxes. It should be ok, as many non-root applications should be allowed to log things etc. But imagine that you will send a lot of very long messages there, different everytime in order not to get stripped into kinda 'message repeated x times'. In this way, you can imho flood syslogd successfully, possibly filling whole partition where /var/log resides, regardless to your quota settings on the machine! Then, if /var/log is not on separate partition, the whole system can get into serious problems, and especially, further events won't be obviously logged, so you can do evil things there happily and nobody will know about it. Discussion? Something i didn't take into account? Possible solutions? -- Petr "Pasky" Baudis . . n = ((n >> 1) & 0x55555555) | ((n << 1) & 0xaaaaaaaa); n = ((n >> 2) & 0x33333333) | ((n << 2) & 0xcccccccc); n = ((n >> 4) & 0x0f0f0f0f) | ((n << 4) & 0xf0f0f0f0); n = ((n >> 8) & 0x00ff00ff) | ((n << 8) & 0xff00ff00); n = ((n >> 16) & 0x0000ffff) | ((n << 16) & 0xffff0000); -- C code which reverses the bits in a word. . . My public PGP key is on: http://pasky.ji.cz/~pasky/pubkey.txt -----BEGIN GEEK CODE BLOCK----- Version: 3.12 GCS d- s++:++ a--- C+++ UL++++$ P+ L+++ E--- W+ N !o K- w-- !O M- !V PS+ !PE Y+ PGP+>++ t+ 5 X(+) R++ tv- b+ DI(+) D+ G e-> h! r% y? ------END GEEK CODE BLOCK------
Current thread:
- Possible syslogd DoS ? Petr Baudis (Oct 03)
- Re: Possible syslogd DoS ? Crist J. Clark (Oct 04)
- Re: Possible syslogd DoS ? VeNoMouS (Oct 04)
- Re: Possible syslogd DoS ? VeNoMouS (Oct 04)
- Re: Possible syslogd DoS ? Petr Baudis (Oct 04)
- Re: Possible syslogd DoS ? Petr Baudis (Oct 05)
- Re: Possible syslogd DoS ? H D Moore (Oct 05)
- Re: Possible syslogd DoS ? Tim Walberg (Oct 05)
- Re: Possible syslogd DoS ? Petr Baudis (Oct 05)
- AnalogX Proxy SMTP server relay Claymore (Oct 05)
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