expat/backport-CVE-2013-0340-Changes-Document-protection-against-billion-laughs-a.patch

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From 3f2f8786623cc3e89a1f4384715b3ad178c5ee2c Mon Sep 17 00:00:00 2001
From: Sebastian Pipping <sebastian@pipping.org>
Date: Mon, 19 Apr 2021 15:08:17 +0200
Subject: [PATCH] Changes: Document protection against billion laughs attacks
---
Changes | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
diff --git a/Changes b/Changes
index 2ecc8a0..a435999 100644
--- a/Changes
+++ b/Changes
@@ -3,10 +3,39 @@ NOTE: We are looking for help with a few things:
If you can help, please get in touch. Thanks!
Release 2.2.9 Wed Septemper 25 2019
+ Security fixes:
+ #34 #466 CVE-2013-0340/CWE-776 -- Protect against billion laughs attacks
+ (denial-of-service; flavors targeting CPU time or RAM or both,
+ leveraging general entities or parameter entities or both)
+ by tracking and limiting the input amplification factor
+ (<amplification> := (<direct> + <indirect>) / <direct>).
+ By conservative default, amplification up to a factor of 100.0
+ is tolerated and rejection only starts after 8 MiB of output bytes
+ (=<direct> + <indirect>) have been processed.
+ A new error code XML_ERROR_AMPLIFICATION_LIMIT_BREACH signals
+ this condition.
+
Bug fixes:
#390 #395 Fix undefined behavior during parsing when compiled with
-DXML_UNICODE that was introduced with Expat 2.0.1
+ New features:
+ #34 #466 Add two new API functions to further tighten billion laughs
+ protection parameters when desired.
+ - XML_SetBillionLaughsAttackProtectionMaximumAmplification
+ - XML_SetBillionLaughsAttackProtectionActivationThreshold
+ Please see file "doc/reference.html" for more details.
+ If you ever need to increase the defaults for non-attack XML
+ payload, please file a bug report with libexpat.
+ #34 #466 Introduce environment switches EXPAT_ACCOUNTING_DEBUG=(0|1|2|3)
+ and EXPAT_ENTITY_DEBUG=(0|1) for runtime debugging of accounting
+ and entity processing; specific behavior of these values may
+ change in the future.
+ #34 #466 xmlwf: Add arguments "-a FACTOR" and "-b BYTES" to further tighten
+ billion laughs protection parameters when desired.
+ If you ever need to increase the defaults for non-attack XML
+ payload, please file a bug report with libexpat.
+
Other changes:
examples: Drop executable bits from elements.c
#349 Windows: Change the name of the Windows DLLs from expat*.dll
@@ -20,6 +49,11 @@ Release 2.2.9 Wed Septemper 25 2019
Special thanks to:
Ben Wagner
+ Nick Wellnhofer
+ Yury Gribov
+ and
+ Clang LeakSan
+ JetBrains
Release 2.2.8 Fri Septemper 13 2019
Security fixes:
--
1.8.3.1