FreeBSD security Advisories: FreeBSD-SA-03:09.sign

Dan writes "FreeBSD security team has released two new advisories. The first advisory entitled "Insufficient range checking of signal numbers" could allow a malicious local user to use this vulnerability as a local denial-of-service attack. The second advisory "Kernel memory disclosure via ibcs2" could allow a malicious user to call the iBCS2 version of statfs(2) with an arbitrarily large length parameter, causing the kernel to return a large portion of kernel memory containing sensitive information."

Comments

Here's the text in case it gets /.'ed

[DrSkwid]

nah, who am I kidding

the signal thing is more than a D.O.S. though

However, in FreeBSD 5.x, the assertion code is not present if the
`INVARIANTS' kernel option is not used. In FreeBSD 5.0-RELEASE and
5.1-RELEASE, `INVARIANTS' is not enabled by default. In this
configuration, a malicious local user could use this vulnerability
to modify kernel memory, potentially leading to complete system
compromise. (FreeBSD 4.x is not vulnerable in this way.)

Re:Malloc(sizeof(ram.total) - sizeof(ram.used));

[ffsnjb]

uncomment the
NO_MODULES= true # do not build modules with the kernel

line in /etc/make.conf

I don't build modules on my production machines, there is no need. This prevents that.