oss-sec mailing list archives

Re: CVE request - slock, all versions NULL pointer dereference


From: cve-assign () mitre org
Date: Thu, 18 Aug 2016 17:13:12 -0400 (EDT)

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The screen locking application slock (http://tools.suckless.org/slock/)
calls crypt(3) and uses the return value for strcmp(3) without checking
to see if the return value of crypt(3) was a NULL pointer. If the hash
returned by (getspnam()->sp_pwdp) is invalid, crypt(3) will return NULL
and set errno to EINVAL. This will cause slock to segfault which then
leaves the machine unprotected. A couple of common scenarios where this
might happen are:

- a machine using NSS for authentication; on the machine I discovered
  this bug, (getspnam()->sp_pwdp) returns "*".
- the user's account has been disabled for one reason or another; maybe
  account expiry or password expiry.

Use CVE-2016-6866.

- -- 
CVE Assignment Team
M/S M300, 202 Burlington Road, Bedford, MA 01730 USA
[ A PGP key is available for encrypted communications at
  http://cve.mitre.org/cve/request_id.html ]
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