CVE-2011-4087

The br_parse_ip_options function in net/bridge/br_netfilter.c in the Linux kernel before 2.6.39 does not properly initialize a certain data structure, which allows remote attackers to cause a denial of service by leveraging connectivity to a network interface that uses an Ethernet bridge device.

Weakness

The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, in Java, if the programmer does not explicitly initialize a variable, then the code could produce a compile-time error (if the variable is local) or automatically initialize the variable to the default value for the variable’s type. In Perl, if explicit initialization is not performed, then a default value of undef is assigned, which is interpreted as 0, false, or an equivalent value depending on the context in which the variable is accessed.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/29.html

References

• http://ftp.osuosl.org/pub/linux/kernel/v2.6/ChangeLog-2.6.39
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=f8e9881c2aef1e982e5abc25c046820cd0b7cf64
• http://www.openwall.com/lists/oss-security/2011/10/28/14
• https://github.com/torvalds/linux/commit/f8e9881c2aef1e982e5abc25c046820cd0b7cf64