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!19 fix CVE-2021-3672

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From: @eaglegai
Reviewed-by: @wangxp006
Signed-off-by: @wangxp006
This commit is contained in:
openeuler-ci-bot 2021-08-13 03:25:21 +00:00 committed by Gitee
commit 9104f2a159
3 changed files with 198 additions and 2 deletions
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83
backport-001-CVE-2021-3672.patch Normal file
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@ -0,0 +1,83 @@
From 362f91d807d293791008cdb7616d40f7784ece83 Mon Sep 17 00:00:00 2001
From: bradh352 <brad@brad-house.com>
Date: Fri, 11 Jun 2021 11:27:45 -0400
Subject: [PATCH] ares_expand_name() should escape more characters
RFC1035 5.1 specifies some reserved characters and escaping sequences
that are allowed to be specified. Expand the list of reserved characters
and also escape non-printable characters using the \DDD format as
specified in the RFC.
Bug Reported By: philipp.jeitner@sit.fraunhofer.de
Fix By: Brad House (@bradh352)
---
src/lib/ares_expand_name.c | 41 +++++++++++++++++++++++++++++++++++---
1 file changed, 38 insertions(+), 3 deletions(-)
diff --git a/src/lib/ares_expand_name.c b/src/lib/ares_expand_name.c
index 407200ef..f1c874a9 100644
--- a/src/lib/ares_expand_name.c
+++ b/src/lib/ares_expand_name.c
@@ -32,6 +32,26 @@
static int name_length(const unsigned char *encoded, const unsigned char *abuf,
int alen);
+/* Reserved characters for names that need to be escaped */
+static int is_reservedch(int ch)
+{
+ switch (ch) {
+ case '"':
+ case '.':
+ case ';':
+ case '\\':
+ case '(':
+ case ')':
+ case '@':
+ case '$':
+ return 1;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
/* Expand an RFC1035-encoded domain name given by encoded. The
* containing message is given by abuf and alen. The result given by
* *s, which is set to a NUL-terminated allocated buffer. *enclen is
@@ -111,9 +131,18 @@ int ares_expand_name(const unsigned char *encoded, const unsigned char *abuf,
p++;
while (len--)
{
- if (*p == '.' || *p == '\\')
+ if (!isprint(*p)) {
+ /* Output as \DDD for consistency with RFC1035 5.1 */
+ *q++ = '\\';
+ *q++ = '0' + *p / 100;
+ *q++ = '0' + (*p % 100) / 10;
+ *q++ = '0' + (*p % 10);
+ } else if (is_reservedch(*p)) {
*q++ = '\\';
- *q++ = *p;
+ *q++ = *p;
+ } else {
+ *q++ = *p;
+ }
p++;
}
*q++ = '.';
@@ -171,7 +200,13 @@ static int name_length(const unsigned char *encoded, const unsigned char *abuf,
encoded++;
while (offset--)
{
- n += (*encoded == '.' || *encoded == '\\') ? 2 : 1;
+ if (!isprint(*encoded)) {
+ n += 4;
+ } else if (is_reservedch(*encoded)) {
+ n += 2;
+ } else {
+ n += 1;
+ }
encoded++;
}
n++;

108
backport-002-CVE-2021-3672.patch Normal file
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@ -0,0 +1,108 @@
From 44c009b8e62ea1929de68e3f438181bea469ec14 Mon Sep 17 00:00:00 2001
From: bradh352 <brad@brad-house.com>
Date: Fri, 11 Jun 2021 12:39:24 -0400
Subject: [PATCH] ares_expand_name(): fix formatting and handling of root name
response
Fixes issue introduced in prior commit with formatting and handling
of parsing a root name response which should not be escaped.
Fix By: Brad House
---
src/lib/ares_expand_name.c | 62 ++++++++++++++++++++++++--------------
1 file changed, 40 insertions(+), 22 deletions(-)
diff --git a/src/lib/ares_expand_name.c b/src/lib/ares_expand_name.c
index f1c874a9..eb9268c1 100644
--- a/src/lib/ares_expand_name.c
+++ b/src/lib/ares_expand_name.c
@@ -127,27 +127,37 @@ int ares_expand_name(const unsigned char *encoded, const unsigned char *abuf,
}
else
{
- len = *p;
+ int name_len = *p;
+ len = name_len;
p++;
+
while (len--)
{
- if (!isprint(*p)) {
- /* Output as \DDD for consistency with RFC1035 5.1 */
- *q++ = '\\';
- *q++ = '0' + *p / 100;
- *q++ = '0' + (*p % 100) / 10;
- *q++ = '0' + (*p % 10);
- } else if (is_reservedch(*p)) {
- *q++ = '\\';
- *q++ = *p;
- } else {
- *q++ = *p;
- }
+ /* Output as \DDD for consistency with RFC1035 5.1, except
+ * for the special case of a root name response */
+ if (!isprint(*p) && !(name_len == 1 && *p == 0))
+ {
+
+ *q++ = '\\';
+ *q++ = '0' + *p / 100;
+ *q++ = '0' + (*p % 100) / 10;
+ *q++ = '0' + (*p % 10);
+ }
+ else if (is_reservedch(*p))
+ {
+ *q++ = '\\';
+ *q++ = *p;
+ }
+ else
+ {
+ *q++ = *p;
+ }
p++;
}
*q++ = '.';
}
- }
+ }
+
if (!indir)
*enclen = aresx_uztosl(p + 1U - encoded);
@@ -194,21 +204,29 @@ static int name_length(const unsigned char *encoded, const unsigned char *abuf,
}
else if (top == 0x00)
{
- offset = *encoded;
+ int name_len = *encoded;
+ offset = name_len;
if (encoded + offset + 1 >= abuf + alen)
return -1;
encoded++;
+
while (offset--)
{
- if (!isprint(*encoded)) {
- n += 4;
- } else if (is_reservedch(*encoded)) {
- n += 2;
- } else {
- n += 1;
- }
+ if (!isprint(*encoded) && !(name_len == 1 && *encoded == 0))
+ {
+ n += 4;
+ }
+ else if (is_reservedch(*encoded))
+ {
+ n += 2;
+ }
+ else
+ {
+ n += 1;
+ }
encoded++;
}
+
n++;
}
else

9
c-ares.spec
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@ -1,6 +1,6 @@
Name: c-ares
Version: 1.17.1
Release: 1
Release: 2
Summary: A C library for asynchronous DNS requests
License: MIT
@ -9,7 +9,9 @@ Source0: https://github.com/c-ares/c-ares/releases/download/cares-1_17_1/
BuildRequires: gcc autoconf automake libtool
# Patch0 from Redhat is applied for stopping overriding AC_CONFIG_MACRO_DIR
Patch0000: 0000-Use-RPM-compiler-options.patch
Patch0: 0000-Use-RPM-compiler-options.patch
Patch1: backport-001-CVE-2021-3672.patch
Patch2: backport-002-CVE-2021-3672.patch
%description
This is c-ares, an asynchronous resolver library. It is intended for applications
which need to perform DNS queries without blocking, or need to perform multiple
@ -52,6 +54,9 @@ make %{?_smp_mflags}
%{_mandir}/man3/*
%changelog
* Thu Aug 12 2021 gaihuiying <gaihuiying1@huawei.com> - 1.17.1-2
- fix CVE-2021-3672
* Sat Jan 30 2021 xihaochen <xihaochen@huawei.com> - 1.17.1-1
- Type:requirements
- Id:NA