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CVE-2004-0461: DHCPD contains C Includes that sometimes defines vsnprintf() as vsprintf()
Author: Cathy Almond Reference Number: AA-00960 Views: 3335 Created: 2013-05-29 14:31 Last Updated: 2013-05-30 11:41 0 Rating/ Voters

DHCPD, when compiled in environments that do not provide the vsnprintf function, uses C include files that define vsnprintf to use the less safe vsprintf function

Posting date: 
22 Jun 2004
Program Impacted: 
DHCP
Versions affected: 
3.0.1rc12, 3.0.1rc13
Severity: 
Medium
Exploitable: 
Remotely

Description:

ISC DHCP makes use of the vsnprintf() function for writing various log file strings. For systems that do not support vsnprintf(), a C include file was created that defines the vsnprintf() function to vsprintf() as such:

#define vsnprintf(buf, size, fmt, list) vsprintf (buf, fmt, list)

vsprintf() is a function that does not check bounds, therefore the size is discarded creating the potential for a buffer overflow when client provided data is supplied. Note that the vsnprintf() statements are defined after the vulnerable code that is discussed in VU#317350. This means that VU#317350 would be triggered prior to these potential buffer overflows, unless a client could specify content to a vsnprintf() statement not associated with logging. It is believed that there aren't any other vsnprintf() statements vulnerable to this type of exploitation.

Workarounds:

None.

Active exploits:

None known at this time.

Solution: 

Upgrade to a released version of ISC DHCPD.

Related Documents:

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Note: ISC patches only currently supported versions. When possible we indicate EOL versions affected.

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This Knowledge Base article https://kb.isc.org/article/AA-00960 is the complete and official security advisory document.

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