* [meta-oe][dunfell][PATCH] c-ares: Add fix for CVE-2021-3672
@ 2021-09-20 12:52 akash hadke
0 siblings, 0 replies; only message in thread
From: akash hadke @ 2021-09-20 12:52 UTC (permalink / raw)
To: openembedded-devel
Cc: nisha.parrakat, ranjitsinh.rathod, Neetika Singh, akash hadke
From: Neetika Singh <Neetika.Singh@kpit.com>
Added below patches to fix CVE-2021-3672
1. ares_expand_name-should-escape-more-characters.patch
2. ares_expand_name-fix-formatting-and-handling-of-root.patch
Link: http://snapshot.debian.org/archive/debian-security/20210810T064453Z/pool/updates/main/c/c-ares/c-ares_1.17.1-1%2Bdeb11u1.debian.tar.xz
Signed-off-by: akash hadke <Akash.Hadke@kpit.com>
Signed-off-by: Neetika Singh <Neetika.Singh@kpit.com>
---
..._name-fix-formatting-and-handling-of-root.patch | 115 +++++++++++++++++++++
...expand_name-should-escape-more-characters.patch | 90 ++++++++++++++++
meta-oe/recipes-support/c-ares/c-ares_1.16.1.bb | 2 +
3 files changed, 207 insertions(+)
create mode 100644 meta-oe/recipes-support/c-ares/c-ares/ares_expand_name-fix-formatting-and-handling-of-root.patch
create mode 100644 meta-oe/recipes-support/c-ares/c-ares/ares_expand_name-should-escape-more-characters.patch
diff --git a/meta-oe/recipes-support/c-ares/c-ares/ares_expand_name-fix-formatting-and-handling-of-root.patch b/meta-oe/recipes-support/c-ares/c-ares/ares_expand_name-fix-formatting-and-handling-of-root.patch
new file mode 100644
index 0000000..d1cb54a
--- /dev/null
+++ b/meta-oe/recipes-support/c-ares/c-ares/ares_expand_name-fix-formatting-and-handling-of-root.patch
@@ -0,0 +1,115 @@
+From: bradh352 <brad@brad-house.com>
+Date: Fri, 11 Jun 2021 12:39:24 -0400
+Subject: [2/2] ares_expand_name(): fix formatting and handling of root name
+ response
+Origin: https://github.com/c-ares/c-ares/commit/44c009b8e62ea1929de68e3f438181bea469ec14
+Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2021-3672
+
+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
+CVE: CVE-2021-3672
+Upstream-Status: Backport [http://snapshot.debian.org/archive/debian-security/20210810T064453Z/pool/updates/main/c/c-ares/c-ares_1.17.1-1%2Bdeb11u1.debian.tar.xz]
+Signed-off-by: Neetika Singh <Neetika.Singh@kpit.com>
+---
+ ares_expand_name.c | 62 ++++++++++++++++++++++++--------------
+ 1 file changed, 40 insertions(+), 22 deletions(-)
+
+diff --git a/ares_expand_name.c b/ares_expand_name.c
+index f1c874a97cfc..eb9268c1ff0a 100644
+--- a/ares_expand_name.c
++++ b/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
+--
+2.32.0
+
diff --git a/meta-oe/recipes-support/c-ares/c-ares/ares_expand_name-should-escape-more-characters.patch b/meta-oe/recipes-support/c-ares/c-ares/ares_expand_name-should-escape-more-characters.patch
new file mode 100644
index 0000000..3603ef1
--- /dev/null
+++ b/meta-oe/recipes-support/c-ares/c-ares/ares_expand_name-should-escape-more-characters.patch
@@ -0,0 +1,90 @@
+From: bradh352 <brad@brad-house.com>
+Date: Fri, 11 Jun 2021 11:27:45 -0400
+Subject: [1/2] ares_expand_name() should escape more characters
+Origin: https://github.com/c-ares/c-ares/commit/362f91d807d293791008cdb7616d40f7784ece83
+Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2021-3672
+
+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)
+CVE: CVE-2021-3672
+Upstream-Status: Backport [http://snapshot.debian.org/archive/debian-security/20210810T064453Z/pool/updates/main/c/c-ares/c-ares_1.17.1-1%2Bdeb11u1.debian.tar.xz]
+Signed-off-by: Neetika Singh <Neetika.Singh@kpit.com>
+---
+ ares_expand_name.c | 41 +++++++++++++++++++++++++++++++++++---
+ 1 file changed, 38 insertions(+), 3 deletions(-)
+
+diff --git a/ares_expand_name.c b/ares_expand_name.c
+index 407200ef5b4b..f1c874a97cfc 100644
+--- a/ares_expand_name.c
++++ b/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++;
+--
+2.32.0
+
diff --git a/meta-oe/recipes-support/c-ares/c-ares_1.16.1.bb b/meta-oe/recipes-support/c-ares/c-ares_1.16.1.bb
index 67dd701..36bb9be 100644
--- a/meta-oe/recipes-support/c-ares/c-ares_1.16.1.bb
+++ b/meta-oe/recipes-support/c-ares/c-ares_1.16.1.bb
@@ -11,6 +11,8 @@ SRC_URI = "\
git://github.com/c-ares/c-ares.git \
file://cmake-install-libcares.pc.patch \
file://0001-fix-configure-error-mv-libcares.pc.cmakein-to-libcar.patch \
+ file://ares_expand_name-should-escape-more-characters.patch \
+ file://ares_expand_name-fix-formatting-and-handling-of-root.patch \
"
SRCREV = "74a1426ba60e2cd7977e53a22ef839c87415066e"
--
2.7.4
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2021-09-20 12:52 [meta-oe][dunfell][PATCH] c-ares: Add fix for CVE-2021-3672 akash hadke
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