Page History

Performing operations on device files that are intended for ordinary character or binary files can result in crashes and denial-of-service attacks.  For example, when Windows attempts to interpret the device name as a file resource, it performs an invalid resource access that usually results in a crash \[[Howard 02|AA. C References#Howard 02]\] .

Device files in UNIX can be a security risk when an attacker can access them in an unauthorized way. For instance, if attackers can read or write to the {{/dev/kmem}} device, they may be able to alter their priority, UID, or other attributes of their process or simply crash the system. Similarly, access to disk devices, tape devices, network devices, and terminals being used by other processes all can lead to problems \[[Garfinkel 96|AA. C References#Garfinkel 96]\].

POSIX defines the {{O_NONBLOCK}} flag to {{open()}}, which ensures that delayed operations on a file do not hang the program \[[Open Group 04|AA. C References#Open Group 04]\].

\[[Garfinkel 96|AA. C References#Garfinkel 96]\] Section 5.6, "Device Files"
\[[Howard 02|AA. C References#Howard 02]\] Chapter 11, "Canonical Representation Issues"
\[[MITRE 07|AA. C References#MITRE 07]\] [CWE ID 67|http://cwe.mitre.org/data/definitions/67.html], "Failure to Handle Windows Device Names"
\[[ISO/IEC 9899:1999|AA. C References#ISO/IEC 9899-1999]\] Section 7.19.4, "Operations on Files"
\[[Open Group 04|AA. C References#Open Group 04]\] [{{open()}}|http://www.opengroup.org/onlinepubs/009695399/functions/open.html]