diff --git a/SOURCES/0002-fix-CVE-2021-3672.patch b/SOURCES/0002-fix-CVE-2021-3672.patch new file mode 100644 index 0000000..9dc7f31 --- /dev/null +++ b/SOURCES/0002-fix-CVE-2021-3672.patch @@ -0,0 +1,198 @@ +From 4bde615c5fa2a6a6f61ca533e46a062691d83f45 Mon Sep 17 00:00:00 2001 +From: bradh352 +Date: Fri, 11 Jun 2021 11:27:45 -0400 +Subject: [PATCH 1/2] 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) +--- + 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 3a38e67..8604543 100644 +--- a/ares_expand_name.c ++++ b/ares_expand_name.c +@@ -38,6 +38,26 @@ + 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 +@@ -117,9 +137,18 @@ 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++ = '.'; +@@ -177,7 +206,13 @@ 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++; +-- +2.26.3 + + +From 86cc9241f89c1155111b992ccc03bf76d8ae634a Mon Sep 17 00:00:00 2001 +From: bradh352 +Date: Fri, 11 Jun 2021 12:39:24 -0400 +Subject: [PATCH 2/2] 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 +--- + 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 8604543..f89ee3f 100644 +--- a/ares_expand_name.c ++++ b/ares_expand_name.c +@@ -133,27 +133,37 @@ 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); + +@@ -200,21 +210,29 @@ 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 +-- +2.26.3 + diff --git a/SPECS/c-ares.spec b/SPECS/c-ares.spec index 3ae25ce..0a692cf 100644 --- a/SPECS/c-ares.spec +++ b/SPECS/c-ares.spec @@ -1,7 +1,7 @@ Summary: A library that performs asynchronous DNS operations Name: c-ares Version: 1.13.0 -Release: 5%{?dist} +Release: 6%{?dist} License: MIT Group: System Environment/Libraries URL: http://c-ares.haxx.se/ @@ -9,6 +9,7 @@ Source0: http://c-ares.haxx.se/download/%{name}-%{version}.tar.gz # The license can be obtained at http://c-ares.haxx.se/license.html Source1: LICENSE Patch0: 0001-Use-RPM-compiler-options.patch +Patch1: 0002-fix-CVE-2021-3672.patch BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n) @@ -34,6 +35,7 @@ compile applications or shared objects that use c-ares. %prep %setup -q %patch0 -p1 -b .optflags +%patch1 -p1 -b .dns cp %{SOURCE1} . f=CHANGES ; iconv -f iso-8859-1 -t utf-8 $f -o $f.utf8 ; mv $f.utf8 $f @@ -72,6 +74,9 @@ rm -rf $RPM_BUILD_ROOT %{_mandir}/man3/ares_* %changelog +* Fri Oct 15 2021 Alexey Tikhonov - 1.13.0-6 +- Resolves: rhbz#1989425 - CVE-2021-3672 c-ares: missing input validation of host names may lead to Domain Hijacking [rhel-8] + * Mon Aug 13 2018 Jakub Hrozek - 1.13.0-5 - Drop an unused patch