haproxy/SOURCES/bz1664533-fix-handling-priority-flag-HTTP2-decoder.patch
2021-10-08 11:44:24 +00:00

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1.2 KiB
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From 57c9ecf43f1ae0211367d8ba79540e3a5d288d34 Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Mon, 31 Dec 2018 07:41:24 +0100
Subject: BUG/CRITICAL: mux-h2: re-check the frame length when PRIORITY is used
MIME-Version: 1.0
Content-Type: text/plain; charset=latin1
Content-Transfer-Encoding: 8bit
Tim Düsterhus reported a possible crash in the H2 HEADERS frame decoder
when the PRIORITY flag is present. A check is missing to ensure the 5
extra bytes needed with this flag are actually part of the frame. As per
RFC7540#4.2, let's return a connection error with code FRAME_SIZE_ERROR.
Many thanks to Tim for responsibly reporting this issue with a working
config and reproducer. This issue was assigned CVE-2018-20615.
This fix must be backported to 1.9 and 1.8.
---
src/mux_h2.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 5803a84ff..a67bbb049 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -3297,6 +3297,11 @@ next_frame:
goto fail;
}
+ if (flen < 5) {
+ h2c_error(h2c, H2_ERR_FRAME_SIZE_ERROR);
+ goto fail;
+ }
+
hdrs += 5; // stream dep = 4, weight = 1
flen -= 5;
}
--
2.20.1