BUG/MAJOR: fcgi: Fix uninitialized reserved bytes

The output buffer is not zero-initialized. If we don't clear reserved
bytes, fcgi requests sent to backend will leak sensitive data.

This patch must be backported as far as 2.2.

diff --git a/src/fcgi.c b/src/fcgi.c
index dcf2db219656d51f7f66717c4ce7e1d2232a500f..1d1a82b4c64484ef964aafef8f2e0b961b3024c0 100644 (file)
--- a/src/fcgi.c
+++ b/src/fcgi.c
@@ -47,7 +47,7 @@ int fcgi_encode_record_hdr(struct buffer *out, const struct fcgi_header *h)
        out->area[len++] = ((h->len >> 8) & 0xff);
        out->area[len++] = (h->len & 0xff);
        out->area[len++] = h->padding;
-       len++; /* rsv */
+       out->area[len++] = 0; /* rsv */
 
        out->data = len;
        return 1;
@@ -94,7 +94,11 @@ int fcgi_encode_begin_request(struct buffer *out, const struct fcgi_begin_reques
        out->area[len++] = ((r->role >> 8) & 0xff);
        out->area[len++] = (r->role & 0xff);
        out->area[len++] = r->flags;
-       len += 5; /* rsv */
+       out->area[len++] = 0; /* rsv */
+       out->area[len++] = 0;
+       out->area[len++] = 0;
+       out->area[len++] = 0;
+       out->area[len++] = 0;
 
        out->data = len;
        return 1;