Hackers Handbook - Millenium Edition/Hackers Handbook.iso/library/hack99/sysklogd_bof.txt

Internet Message Format | 1999-03-24 | 1.7 KB

Date: Tue, 16 Feb 1999 02:22:56 -0500
From: Cory Visi <[e-mail]>
To: [e-mail]
Subject: RedHat sysklogd vulnerability

I'd like to apologize for being so late with this e-mail as I have known
about this problem for months. The vulnerability was discussed in a Thu, 10
Sep 1998 BugTraq e-mail by Michal Zalewski ([e-mail]). I replied to it
with a quick patch. Here are some lines from my e-mail:

> I'm not completely happy with this, as it modifies the reference parameter,
> ptr, but it will solve the problem. However, later on:
>
> ExpandKadds(line, eline)
>
> Where eline is the same size as line. I think the real solution is to make
> sure the buffer is larger (LOG_LINE_LENGTH) like Michal said, and make sure
> modules and programs don't generate obsurdly long messages,  because you
> can't be certain how much room is necessary for the expanded symbols. It
> would be nice if ExpandKadds() allocated memory dynamically, but it doesn't.

RedHat immediately issued a "fix" to their current package: sysklogd-1.3-26
This "fix" is merely my patch (and nothing more). My patch DOES NOT fix the
problem. As discussed by the package co-maintainer (Martin Schulze
([e-mail])) the bug is fixed in the latest sysklogd
package (1.3-30). In fact, the bug was fixed in 1996. What this comes down
to is that any Linux distribution running an old sysklogd package (namely
RedHat all versions) STILL has a potential (rather obscure) buffer overflow.
They need to upgrade to the latest version ASAP. I e-mailed
[e-mail] and got no response.

Thank you,

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