Return error if hostname too long for remote resolve

Resolves: RHEL-11467
This commit is contained in:
Jacek Migacz 2023-10-10 18:25:06 +02:00
parent c20fcd3e87
commit 0783247f07
2 changed files with 144 additions and 1 deletions

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@ -0,0 +1,136 @@
From 1d66562c67fc0099d0fd882c693e51dd0b10c45c Mon Sep 17 00:00:00 2001
From: Jay Satiro <raysatiro@yahoo.com>
Date: Sat, 30 Sep 2023 03:40:02 -0400
Subject: [PATCH] socks: return error if hostname too long for remote resolve
Prior to this change the state machine attempted to change the remote
resolve to a local resolve if the hostname was longer than 255
characters. Unfortunately that did not work as intended and caused a
security issue.
Name resolvers cannot resolve hostnames longer than 255 characters.
Bug: https://curl.se/docs/CVE-2023-38545.html
---
lib/socks.c | 8 +++---
tests/data/Makefile.inc | 2 +-
tests/data/test728 | 64 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 69 insertions(+), 5 deletions(-)
create mode 100644 tests/data/test728
diff --git a/lib/socks.c b/lib/socks.c
index c492d663c..a7b5ab07e 100644
--- a/lib/socks.c
+++ b/lib/socks.c
@@ -531,13 +531,13 @@ CURLproxycode Curl_SOCKS5(const char *proxy_user,
infof(data, "SOCKS5: connecting to HTTP proxy %s port %d\n",
hostname, remote_port);
/* RFC1928 chapter 5 specifies max 255 chars for domain name in packet */
if(!socks5_resolve_local && hostname_len > 255) {
- infof(data, "SOCKS5: server resolving disabled for hostnames of "
- "length > 255 [actual len=%zu]\n", hostname_len);
- socks5_resolve_local = TRUE;
+ failf(data, "SOCKS5: the destination hostname is too long to be "
+ "resolved remotely by the proxy.");
+ return CURLPX_LONG_HOSTNAME;
}
if(auth & ~(CURLAUTH_BASIC | CURLAUTH_GSSAPI))
infof(data,
"warning: unsupported value passed to CURLOPT_SOCKS5_AUTH: %lu\n",
@@ -855,7 +855,7 @@ CONNECT_RESOLVE_REMOTE:
if(!socks5_resolve_local) {
socksreq[len++] = 3; /* ATYP: domain name = 3 */
- socksreq[len++] = (char) hostname_len; /* one byte address length */
+ socksreq[len++] = (unsigned char) hostname_len; /* one byte length */
memcpy(&socksreq[len], hostname, hostname_len); /* address w/o NULL */
len += hostname_len;
infof(data, "SOCKS5 connect to %s:%d (remotely resolved)\n",
diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
index 081e344d4..62ee53578 100644
--- a/tests/data/Makefile.inc
+++ b/tests/data/Makefile.inc
@@ -99,7 +99,7 @@ test672 test673 test674 test675 test676 test677 test678 test679 test680 \
\
test700 test701 test702 test703 test704 test705 test706 test707 test708 \
test709 test710 test711 test712 test713 test714 test715 test716 test717 \
-test718 \
+test718 test728 \
\
test800 test801 test802 test803 test804 test805 test806 test807 test808 \
test809 test810 test811 test812 test813 test814 test815 test816 test817 \
diff --git a/tests/data/test728 b/tests/data/test728
new file mode 100644
index 000000000..05bcf2883
--- /dev/null
+++ b/tests/data/test728
@@ -0,0 +1,64 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP GET
+SOCKS5
+SOCKS5h
+followlocation
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+# The hostname in this redirect is 256 characters and too long (> 255) for
+# SOCKS5 remote resolve. curl must return error CURLE_PROXY in this case.
+<data>
+HTTP/1.1 301 Moved Permanently
+Location: http://AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/
+Content-Length: 0
+Connection: close
+
+</data>
+</reply>
+
+#
+# Client-side
+<client>
+<features>
+proxy
+</features>
+<server>
+http
+socks5
+</server>
+ <name>
+SOCKS5h with HTTP redirect to hostname too long
+ </name>
+ <command>
+--no-progress-meter --location --proxy socks5h://%HOSTIP:%SOCKSPORT http://%HOSTIP:%HTTPPORT/%TESTNUMBER
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<protocol crlf="yes">
+GET /%TESTNUMBER HTTP/1.1
+Host: %HOSTIP:%HTTPPORT
+User-Agent: curl/%VERSION
+Accept: */*
+
+</protocol>
+<errorcode>
+97
+</errorcode>
+# the error message is verified because error code CURLE_PROXY (97) may be
+# returned for any number of reasons and we need to make sure it is
+# specifically for the reason below so that we know the check is working.
+<stderr mode="text">
+curl: (97) SOCKS5: the destination hostname is too long to be resolved remotely by the proxy.
+</stderr>
+</verify>
+</testcase>
--
2.42.0

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@ -1,7 +1,7 @@
Summary: A utility for getting files from remote servers (FTP, HTTP, and others)
Name: curl
Version: 7.76.1
Release: 27%{?dist}
Release: 28%{?dist}
License: MIT
Source: https://curl.se/download/%{name}-%{version}.tar.xz
@ -98,6 +98,9 @@ Patch31: 0031-curl-7.76.1-CVE-2023-28321.patch
# when keyboard-interactive auth fails, try password
Patch32: 0032-curl-7.76.1-password-when-keyboard-interactive-fails.patch
# return error if hostname too long for remote resolve
Patch33: 0033-curl-7.76.1-CVE-2023-38545.patch
# patch making libcurl multilib ready
Patch101: 0101-curl-7.32.0-multilib.patch
@ -304,6 +307,7 @@ be installed.
%patch30 -p1
%patch31 -p1
%patch32 -p1
%patch33 -p1
# Fedora patches
%patch101 -p1
@ -529,6 +533,9 @@ rm -f ${RPM_BUILD_ROOT}%{_libdir}/libcurl.la
%{_libdir}/libcurl.so.4.[0-9].[0-9].minimal
%changelog
* Tue Oct 10 2023 Jacek Migacz <jmigacz@redhat.com> - 7.76.1-28
- return error if hostname too long for remote resolve (CVE-2023-38545)
* Tue Sep 12 2023 Jacek Migacz <jmigacz@redhat.com> - 7.76.1-27
- when keyboard-interactive auth fails, try password (#2229800)