diff --git a/ChangeLog b/ChangeLog
index 210402a73..010c450b8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,10 @@
    - djm@cvs.openbsd.org 2004/02/25 00:22:45
      [sshd.c]
      typo in comment
+   - dtucker@cvs.openbsd.org 2004/02/27 22:42:47
+     [dh.c]
+     Prevent sshd from sending DH groups with a primitive generator of zero or
+     one, even if they are listed in /etc/moduli.  ok markus@
 
 20040226
  - (bal) KNF our sshlogin.c even if the code looks nothing like upstream
@@ -808,4 +812,4 @@
    - (djm) Trim deprecated options from INSTALL. Mention UsePAM
    - (djm) Fix quote handling in sftp; Patch from admorten AT umich.edu
 
-$Id: ChangeLog,v 1.3261 2004/02/29 09:11:30 dtucker Exp $
+$Id: ChangeLog,v 1.3262 2004/02/29 09:12:33 dtucker Exp $
diff --git a/dh.c b/dh.c
index c7a3e18be..b58b8bc28 100644
--- a/dh.c
+++ b/dh.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: dh.c,v 1.26 2003/12/16 15:51:54 markus Exp $");
+RCSID("$OpenBSD: dh.c,v 1.27 2004/02/27 22:42:47 dtucker Exp $");
 
 #include "xmalloc.h"
 
@@ -91,6 +91,9 @@ parse_prime(int linenum, char *line, struct dhgroup *dhg)
 	if (BN_num_bits(dhg->p) != dhg->size)
 		goto failclean;
 
+	if (BN_is_zero(dhg->g) || BN_is_one(dhg->g))
+		goto failclean;
+
 	return (1);
 
  failclean: