Public Vulnerability Reports

SCO Unixware Setuid ppp prompt Buffer Overflow Vulnerability



SCO UnixWare is a UNIX operating system.

More information is available at:


Local exploitation of a buffer overflow vulnerability in the ppp binary,
as included in multiple versions of The SCO Group Inc.'s Unixware,
allows attackers to gain root privileges.

The vulnerability specifically exists because of a failure to check the
length of user input. If the user running the ppp program enters an
argument to the "prompt" or "defprompt" command that exceeds 256 bytes in
length, a stack based overflow occurs. This leads to the execution of
arbitrary code with root privileges, as ppp is setuid root by default.


Successful exploitation of this vulnerability requires that user have
local access to the system; it would allow the user to gain superuser


iDEFENSE has confirmed the existence of this vulnerability in SCO
Unixware versions 7.1.3 and 7.1.4. All versions of SCO Unixware are
suspected to be vulnerable.


As a workaround solution, remove the setuid bit from the ppp binary
until a vendor patch can be applied.

  # chmod u-s /usr/bin/ppp


The vendor has released the following advisory for this issue:


The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2005-2927 to this issue. This is a candidate for inclusion in
the CVE list (, which standardizes names for
security problems.


09/08/2005   Initial vendor notification
09/09/2005   Initial vendor response
10/24/2005   Public disclosure


iDEFENSE Labs is credited with the discovery of this vulnerability.

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Copyright © 2005 Verisign, Inc.

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