Support username alias in PlainUsers

Resolves: RHEL-8430
This commit is contained in:
Jan Grulich 2023-10-09 09:03:02 +02:00
parent b1e183de26
commit ebd2a0d7a1
2 changed files with 142 additions and 1 deletions

View File

@ -0,0 +1,135 @@
diff --git a/common/rfb/SSecurityPlain.cxx b/common/rfb/SSecurityPlain.cxx
index 6f65e87..3142ba3 100644
--- a/common/rfb/SSecurityPlain.cxx
+++ b/common/rfb/SSecurityPlain.cxx
@@ -27,6 +27,8 @@
#include <rdr/InStream.h>
#if !defined(WIN32) && !defined(__APPLE__)
#include <rfb/UnixPasswordValidator.h>
+#include <unistd.h>
+#include <pwd.h>
#endif
#ifdef WIN32
#include <rfb/WinPasswdValidator.h>
@@ -45,21 +47,22 @@ StringParameter PasswordValidator::plainUsers
bool PasswordValidator::validUser(const char* username)
{
- CharArray users(plainUsers.getValueStr()), user;
+ std::vector<std::string> users;
- while (users.buf) {
- strSplit(users.buf, ',', &user.buf, &users.buf);
-#ifdef WIN32
- if (0 == stricmp(user.buf, "*"))
- return true;
- if (0 == stricmp(user.buf, username))
- return true;
-#else
- if (!strcmp(user.buf, "*"))
- return true;
- if (!strcmp(user.buf, username))
- return true;
+ users = split(plainUsers, ',');
+
+ for (size_t i = 0; i < users.size(); i++) {
+ if (users[i] == "*")
+ return true;
+#if !defined(WIN32) && !defined(__APPLE__)
+ if (users[i] == "%u") {
+ struct passwd *pw = getpwnam(username);
+ if (pw && pw->pw_uid == getuid())
+ return true;
+ }
#endif
+ if (users[i] == username)
+ return true;
}
return false;
}
diff --git a/common/rfb/util.cxx b/common/rfb/util.cxx
index 649eb0b..cce73a0 100644
--- a/common/rfb/util.cxx
+++ b/common/rfb/util.cxx
@@ -99,6 +99,26 @@ namespace rfb {
return false;
}
+ std::vector<std::string> split(const char* src,
+ const char delimiter)
+ {
+ std::vector<std::string> out;
+ const char *start, *stop;
+
+ start = src;
+ do {
+ stop = strchr(start, delimiter);
+ if (stop == NULL) {
+ out.push_back(start);
+ } else {
+ out.push_back(std::string(start, stop-start));
+ start = stop + 1;
+ }
+ } while (stop != NULL);
+
+ return out;
+ }
+
bool strContains(const char* src, char c) {
int l=strlen(src);
for (int i=0; i<l; i++)
diff --git a/common/rfb/util.h b/common/rfb/util.h
index f0ac9ef..ed15c28 100644
--- a/common/rfb/util.h
+++ b/common/rfb/util.h
@@ -27,6 +27,9 @@
#include <limits.h>
#include <string.h>
+#include <string>
+#include <vector>
+
struct timeval;
#ifdef __GNUC__
@@ -76,6 +79,10 @@ namespace rfb {
// that part of the string. Obviously, setting both to 0 is not useful...
bool strSplit(const char* src, const char limiter, char** out1, char** out2, bool fromEnd=false);
+ // Splits a string with the specified delimiter
+ std::vector<std::string> split(const char* src,
+ const char delimiter);
+
// Returns true if src contains c
bool strContains(const char* src, char c);
diff --git a/unix/x0vncserver/x0vncserver.man b/unix/x0vncserver/x0vncserver.man
index c36ae34..78db730 100644
--- a/unix/x0vncserver/x0vncserver.man
+++ b/unix/x0vncserver/x0vncserver.man
@@ -125,8 +125,8 @@ parameter instead.
.B \-PlainUsers \fIuser-list\fP
A comma separated list of user names that are allowed to authenticate via
any of the "Plain" security types (Plain, TLSPlain, etc.). Specify \fB*\fP
-to allow any user to authenticate using this security type. Default is to
-deny all users.
+to allow any user to authenticate using this security type. Specify \fB%u\fP
+to allow the user of the server process. Default is to deny all users.
.
.TP
.B \-pam_service \fIname\fP, \-PAMService \fIname\fP
diff --git a/unix/xserver/hw/vnc/Xvnc.man b/unix/xserver/hw/vnc/Xvnc.man
index ea87dea..e9fb654 100644
--- a/unix/xserver/hw/vnc/Xvnc.man
+++ b/unix/xserver/hw/vnc/Xvnc.man
@@ -200,8 +200,8 @@ parameter instead.
.B \-PlainUsers \fIuser-list\fP
A comma separated list of user names that are allowed to authenticate via
any of the "Plain" security types (Plain, TLSPlain, etc.). Specify \fB*\fP
-to allow any user to authenticate using this security type. Default is to
-deny all users.
+to allow any user to authenticate using this security type. Specify \fB%u\fP
+to allow the user of the server process. Default is to deny all users.
.
.TP
.B \-pam_service \fIname\fP, \-PAMService \fIname\fP

View File

@ -5,7 +5,7 @@
Name: tigervnc
Version: 1.13.1
Release: 2%{?dist}
Release: 3%{?dist}
Summary: A TigerVNC remote display system
%global _hardened_build 1
@ -26,6 +26,7 @@ Patch1: tigervnc-use-gnome-as-default-session.patch
Patch2: tigervnc-vncsession-restore-script-systemd-service.patch
# Upstream patches
Patch50: tigervnc-support-username-alias-in-plainusers.patch
# This is tigervnc-%%{version}/unix/xserver116.patch rebased on the latest xorg
Patch100: tigervnc-xserver120.patch
@ -186,6 +187,7 @@ popd
%patch2 -p1 -b .vncsession-restore-script-systemd-service
# Upstream patches
%patch50 -p1 -b .support-username-alias-in-plainusers
%build
%ifarch sparcv9 sparc64 s390 s390x
@ -368,6 +370,10 @@ fi
%ghost %verify(not md5 size mtime) %{_sharedstatedir}/selinux/%{selinuxtype}/active/modules/200/%{modulename}
%changelog
* Mon Oct 09 2023 Jan Grulich <jgrulich@redhat.com> - 1.13.1-3
- Support username alias in PlainUsers
Resolves: RHEL-8430
* Tue Apr 11 2023 Jan Grulich <jgrulich@redhat.com> - 1.13.1-2
- xorg-x11-server: X.Org Server Overlay Window Use-After-Free Local Privilege
Escalation Vulnerability