[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Mon, 8 Aug 2022 18:31:59 -0700
From: Alan Coopersmith <alan.coopersmith@...cle.com>
To: oss-security@...ts.openwall.com
Cc: Evgeny Legerov <admin@...ndisco.cc>
Subject: Re: zlib buffer overflow
On 8/5/22 13:53, Evgeny Legerov wrote:
> Heap overflow has been fixed in zlib -
> https://www.cve.org/CVERecord?id=CVE-2022-37434
Expanding this for the benefit of list members and the archives:
The CVE description is:
zlib through 1.2.12 has a heap-based buffer over-read or buffer overflow
in inflate in inflate.c via a large gzip header extra field.
NOTE: only applications that call inflateGetHeader are affected. Some
common applications bundle the affected zlib source code but may be unable
to call inflateGetHeader (e.g., see the nodejs/node reference).
where the nodejs reference is to:
https://github.com/nodejs/node/blob/75b68c6e4db515f76df73af476eccf382bbcb00a/deps/zlib/inflate.c#L762-L764
The reproducer is posted at https://github.com/ivd38/zlib_overflow and
notes the issue was found by Evgeny Legerov of @intevydis - who is
presumably our original poster here.
The initial fix upstream was:
If the extra field was larger than the space the user provided with
inflateGetHeader(), and if multiple calls of inflate() delivered
the extra header data, then there could be a buffer overflow of the
provided space. This commit assures that provided space is not
exceeded.
from https://github.com/madler/zlib/commit/eff308af425b67093bab25f80f1ae950166bece1
*but* the curl developers found that crashed in their testing, as reported
in comments on the above commit and https://github.com/curl/curl/issues/9271
so a followup fix upstream today made sure not to dereference state->head
until *after* the check for it not being NULL:
https://github.com/madler/zlib/commit/1eb7682f845ac9e9bf9ae35bbfb3bad5dacbd91d
--
-Alan Coopersmith- alan.coopersmith@...cle.com
Oracle Solaris Engineering - https://blogs.oracle.com/solaris
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.
