Red Hat Bugzilla – Bug 245547
CVE-2007-2442 krb5 RPC library unitialized pointer free
Last modified: 2008-02-26 10:15:04 EST
The MIT Kerberos Team has made us aware of the following issue:
CVE-2007-2442: The RPC library can free an uninitialized pointer.
"CVE-2007-2442: The function gssrpc__svcauth_gssapi() in
src/lib/rpc/svc_auth_gssapi.c declares an automatic variable "creds"
of type auth_gssapi_creds. This type includes a gss_buffer_desc
(which includes a pointer to void used as a pointer to a buffer of
bytes). If gssrpc__svcauth_gssapi() receives an RPC credential with a
length of zero, it jumps to the label "error", which executes some
cleanup code. At this point, the gss_buffer_desc in "creds" is not
yet initialized, and the cleanup code calls xdr_free() on "creds",
which then attempts to free the memory pointed to by the uninitialized
"value" member of the gss_buffer_desc.
Exploitation of freeing of invalid pointers is believed to be
difficult, and depends on a variety of factors specific to a given
This issue is embargoed until 20070626
For Red Hat Enterprise Linux 4 and 5, glibc contains checks that prevent this
issue from being exploitable. Therefore this is a denial of service issue and
is impact important.
For Red Hat Enterprise Linux 2.1 and 3, this issue is potentially exploitable
and could result in arbitrary code execution. Therefore this is is impact critical.
Lifting embargo: http://web.mit.edu/Kerberos/advisories/MITKRB5-SA-2007-004.txt
This issue was addressed in:
Red Hat Enterprise Linux: