1. 13 7月, 2006 1 次提交
    • M
      [PATCH] Fix prctl privilege escalation and suid_dumpable (CVE-2006-2451) · abf75a50
      Marcel Holtmann 提交于
      Based on a patch from Ernie Petrides
      
      During security research, Red Hat discovered a behavioral flaw in core
      dump handling. A local user could create a program that would cause a
      core file to be dumped into a directory they would not normally have
      permissions to write to. This could lead to a denial of service (disk
      consumption), or allow the local user to gain root privileges.
      
      The prctl() system call should never allow to set "dumpable" to the
      value 2. Especially not for non-privileged users.
      
      This can be split into three cases:
      
        1) running as root -- then core dumps will already be done as root,
           and so prctl(PR_SET_DUMPABLE, 2) is not useful
      
        2) running as non-root w/setuid-to-root -- this is the debatable case
      
        3) running as non-root w/setuid-to-non-root -- then you definitely
           do NOT want "dumpable" to get set to 2 because you have the
           privilege escalation vulnerability
      
      With case #2, the only potential usefulness is for a program that has
      designed to run with higher privilege (than the user invoking it) that
      wants to be able to create root-owned root-validated core dumps. This
      might be useful as a debugging aid, but would only be safe if the program
      had done a chdir() to a safe directory.
      
      There is no benefit to a production setuid-to-root utility, because it
      shouldn't be dumping core in the first place. If this is true, then the
      same debugging aid could also be accomplished with the "suid_dumpable"
      sysctl.
      Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      abf75a50
  2. 12 7月, 2006 11 次提交
  3. 11 7月, 2006 28 次提交