Multiple race conditions in the terminal layer in Linux 2.4.x, and 2.6.x before 2.6.9, allow (1) local users to obtain portions of kernel data via a TIOCSETD ioctl call to a terminal interface that is being accessed by another thread, or (2) remote attackers to cause a denial of service (panic) by switching from console to PPP line discipline, then quickly sending data that is received during the switch.
This is a vulnerability exploitable with only local access requires the attacker to have either
physical access to the vulnerable system or a local (shell) account. Examples of locally
exploitable vulnerabilities are peripheral attacks such as Firewire/USB DMA attacks, and
local privilege escalations (e.g., sudo).
Specialized access conditions exist. For example,
in most configurations, the attacking party must already have elevated privileges or spoof additional systems
in addition to the attacking system (e.g., DNS hijacking).
The attack depends on social engineering methods that would be easily detected by knowledgeable people.
For example, the victim must perform several suspicious or atypical actions.
The vulnerable configuration is seen very rarely in practice.
If a race condition exists, the window is very narrow.
Authentication is not required to access and exploit the vulnerability.
There is no impact to the confidentiality of the system.
There is no impact to the integrity of the system.
There is reduced performance or interruptions in resource availability. An example is
a network-based flood attack that permits a limited number of successful connections
to an Internet service.