[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1479102804.3372667.786730489.054A352E@webmail.messagingengine.com>
Date: Mon, 14 Nov 2016 06:53:24 +0100
From: Ondřej Surý <ondrej@...y.org>
To: oss-security@...ts.openwall.com,
Sam Trenholme <sam-k6mymjcnjpz3fmkieotlt7rbgvqt98qy@...iam.org>
Subject: Re: Remote crash in MaraDNS 2.0.13 and git master
Hi all,
AFL found another 5 crashes totaling to 6 unique crashes. Looking at the
backtraces it
looks like, it's just 3 unique crashes:
- js_readuint16
- js_substr
- process_query -> this in fact looks like stack smashing, since it
crashes on htons in an unrelated place
id:000000
id:000002
Program received signal SIGSEGV, Segmentation fault.
js_readuint16 (js=js@...ry=0x6de290, offset=offset@...ry=4) at
JsStr.c:1064
1064 (*(js->string + offset + 1) & 0xff);
id:000001
id:000005
Program received signal SIGSEGV, Segmentation fault.
js_substr (source=source@...ry=0x6de290, dest=dest@...ry=0x6e37f0,
start=start@...ry=99, count=count@...ry=63743) at JsStr.c:731
731 *(source->string + counter + start *
source->unit_size);
NOTE: id000001 cannot be reproduced on git master, but id000005 still
crashes it, so they probably are separate issues after all.
id:000003
id:000004
Program received signal SIGSEGV, Segmentation fault.
proc_query (raw=0x6de5d0, ect=0x7fffffffd940, sock=0) at MaraDNS.c:2615
2615 ip = htonl((z->sin_addr).s_addr);
This is after 58 AFL cycles.
It will be worth retesting with ASAN enabled.
Cheers,
--
Ondřej Surý <ondrej@...y.org>
Knot DNS (https://www.knot-dns.cz/) – a high-performance DNS server
Knot Resolver (https://www.knot-resolver.cz/) – secure, privacy-aware,
fast DNS(SEC) resolver
Vše pro chleba (https://vseprochleba.cz) – Mouky ze mlýna a potřeby pro
pečení chleba všeho druhu
On Sat, Nov 12, 2016, at 09:39, Ondřej Surý wrote:
> Hi,
>
> while playing with fuzzing the DNS servers with AFL (2.35b) I found a
> remote crash bug in MaraDNS 2.0.13 js_readuint16. It can be also
> reproduced using https://github.com/samboy/MaraDNS/ master branch.
>
> Attached is patch to allow the fuzzing (it overrides getudp() with
> read(0, ..)), the input data that crashes MaraDNS, and the bt full
> output.
>
> Please assign CVE, I would provide a patch, but MaraDNS code is
> extremely hard to navigate for me, so I'll leave the fix for the code
> author.
>
> AFL has finished only 1 cycle (and found the 1 unique crash), so I'll
> keep it running for a while.
>
> Cheers,
> --
> Ondřej Surý <ondrej@...y.org>
> Knot DNS (https://www.knot-dns.cz/) – a high-performance DNS server
> Knot Resolver (https://www.knot-resolver.cz/) – secure, privacy-aware,
> fast DNS(SEC) resolver
> Vše pro chleba (https://vseprochleba.cz) – Mouky ze mlýna a potřeby pro
> pečení chleba všeho druhu
> Email had 3 attachments:
> + maradns.btfull
> 5k (application/octet-stream)
> + allow-fuzzing.patch
> 2k (text/x-patch)
> + id:000000,sig:11,src:007564,op:havoc,rep:32
> 1k (application/octet-stream)
Powered by blists - more mailing lists
Please check out the
Open Source Software Security Wiki, which is counterpart to this
mailing list.
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
