[29277] in CVS-changelog-for-Kerberos-V5
krb5 commit [krb5-1.14]: Verify decoded kadmin C strings
daemon@ATHENA.MIT.EDU (Tom Yu)
Mon Feb 8 17:44:25 2016
Date: Mon, 8 Feb 2016 17:44:21 -0500
From: Tom Yu <tlyu@mit.edu>
Message-Id: <201602082244.u18MiLU8002164@drugstore.mit.edu>
To: cvs-krb5@mit.edu
Reply-To: krbdev@mit.edu
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: cvs-krb5-bounces@mit.edu
https://github.com/krb5/krb5/commit/54a9a01c6a923d604cd06f321b8381ebc5cb42d8
commit 54a9a01c6a923d604cd06f321b8381ebc5cb42d8
Author: Greg Hudson <ghudson@mit.edu>
Date: Fri Jan 8 12:45:25 2016 -0500
Verify decoded kadmin C strings [CVE-2015-8629]
In xdr_nullstring(), check that the decoded string is terminated with
a zero byte and does not contain any internal zero bytes.
CVE-2015-8629:
In all versions of MIT krb5, an authenticated attacker can cause
kadmind to read beyond the end of allocated memory by sending a string
without a terminating zero byte. Information leakage may be possible
for an attacker with permission to modify the database.
CVSSv2 Vector: AV:N/AC:H/Au:S/C:P/I:N/A:N/E:POC/RL:OF/RC:C
(cherry picked from commit df17a1224a3406f57477bcd372c61e04c0e5a5bb)
ticket: 8341
version_fixed: 1.14.1
src/lib/kadm5/kadm_rpc_xdr.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)
diff --git a/src/lib/kadm5/kadm_rpc_xdr.c b/src/lib/kadm5/kadm_rpc_xdr.c
index 2bef858..ba67084 100644
--- a/src/lib/kadm5/kadm_rpc_xdr.c
+++ b/src/lib/kadm5/kadm_rpc_xdr.c
@@ -64,7 +64,14 @@ bool_t xdr_nullstring(XDR *xdrs, char **objp)
return FALSE;
}
}
- return (xdr_opaque(xdrs, *objp, size));
+ if (!xdr_opaque(xdrs, *objp, size))
+ return FALSE;
+ /* Check that the unmarshalled bytes are a C string. */
+ if ((*objp)[size - 1] != '\0')
+ return FALSE;
+ if (memchr(*objp, '\0', size - 1) != NULL)
+ return FALSE;
+ return TRUE;
case XDR_ENCODE:
if (size != 0)
_______________________________________________
cvs-krb5 mailing list
cvs-krb5@mit.edu
https://mailman.mit.edu/mailman/listinfo/cvs-krb5
