1 files changed, 14 insertions, 0 deletions
diff --git a/transact.c b/transact.c
index e98be346..cae6b701 100644
--- a/transact.c
+++ b/transact.c
@@ -428,6 +428,8 @@ int readheaders(int sock,
 	linelen = 0;
 	line[0] = '\0';
 	do {
+	    char	*sp, *tp;
+
 	    set_timeout(mytimeout);
 	    if ((n = SockRead(sock, buf, sizeof(buf)-1)) == -1) {
 		set_timeout(0);
@@ -438,6 +440,18 @@ int readheaders(int sock,
 	    }
 	    set_timeout(0);
 
+	    /*
+	     * Smash out any medial NULs, they could wreak havoc later on.
+	     * Some network stacks seem to generate these at random,
+	     * always (according to reports) at the beginning of the
+	     * first read.  NUls are illegal in RFC822 format.
+	     */
+	    for (sp = tp = buf; sp < buf + n; sp++)
+		if (*sp)
+		    *tp++ = *sp;
+	    *tp = '\0';
+	    n = tp - buf;
+
 	    remaining -= n;
 	    linelen += n;
 	    msgblk.msglen += n;