diff --git a/backport-001-CVE-2021-3672.patch b/backport-001-CVE-2021-3672.patch new file mode 100644 index 0000000000000000000000000000000000000000..e72890f96657a47bd55cf45d25fb6821951fbbdc --- /dev/null +++ b/backport-001-CVE-2021-3672.patch @@ -0,0 +1,83 @@ +From 362f91d807d293791008cdb7616d40f7784ece83 Mon Sep 17 00:00:00 2001 +From: bradh352 +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++; diff --git a/backport-002-CVE-2021-3672.patch b/backport-002-CVE-2021-3672.patch new file mode 100644 index 0000000000000000000000000000000000000000..988c6813a7eb86c40af42c83709a175e6fc583aa --- /dev/null +++ b/backport-002-CVE-2021-3672.patch @@ -0,0 +1,108 @@ +From 44c009b8e62ea1929de68e3f438181bea469ec14 Mon Sep 17 00:00:00 2001 +From: bradh352 +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 diff --git a/c-ares.spec b/c-ares.spec index d12b42550dd05ba97dd16b3e47fa277c5c0f138f..5f77132bff51a32e8ef10f6dc9f532acca48b7ea 100644 --- a/c-ares.spec +++ b/c-ares.spec @@ -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 - 1.17.1-2 +- fix CVE-2021-3672 + * Sat Jan 30 2021 xihaochen - 1.17.1-1 - Type:requirements - Id:NA