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sudo update CVE-2021-3156

Signed-off-by: basebuilder_pel7x64builder0 <basebuilder@powerel.org>
master
basebuilder_pel7x64builder0 3 years ago
parent
commit
0a01f7450e
  1. 207
      SOURCES/sudo-1.8.31-CVE-2021-3156.patch
  2. 12
      SPECS/sudo.spec

207
SOURCES/sudo-1.8.31-CVE-2021-3156.patch

@ -0,0 +1,207 @@ @@ -0,0 +1,207 @@
diff -up ./plugins/sudoers/policy.c.heap-buffer ./plugins/sudoers/policy.c
--- ./plugins/sudoers/policy.c.heap-buffer 2021-01-20 13:10:29.368619293 +0100
+++ ./plugins/sudoers/policy.c 2021-01-20 15:56:12.915095745 +0100
@@ -93,11 +93,12 @@ parse_bool(const char *line, int varlen,
int
sudoers_policy_deserialize_info(void *v, char **runas_user, char **runas_group)
{
+ const int edit_mask = MODE_EDIT|MODE_IGNORE_TICKET|MODE_NONINTERACTIVE;
struct sudoers_policy_open_info *info = v;
- char * const *cur;
const char *p, *errstr, *groups = NULL;
const char *remhost = NULL;
bool uid_set = false, gid_set = false;
+ char * const *cur;
int flags = 0;
debug_decl(sudoers_policy_deserialize_info, SUDOERS_DEBUG_PLUGIN)
@@ -326,6 +327,12 @@ sudoers_policy_deserialize_info(void *v,
#endif
}
+ /* Sudo front-end should restrict mode flags for sudoedit. */
+ if (ISSET(flags, MODE_EDIT) && (flags & edit_mask) != flags) {
+ sudo_warnx(U_("invalid mode flags from sudo front end: 0x%x"), flags);
+ goto bad;
+ }
+
user_umask = (mode_t)-1;
for (cur = info->user_info; *cur != NULL; cur++) {
if (MATCHES(*cur, "user=")) {
diff -up ./plugins/sudoers/sudoers.c.heap-buffer ./plugins/sudoers/sudoers.c
--- ./plugins/sudoers/sudoers.c.heap-buffer 2021-01-20 13:10:29.350619537 +0100
+++ ./plugins/sudoers/sudoers.c 2021-01-20 13:10:29.369619280 +0100
@@ -416,7 +416,7 @@ sudoers_policy_main(int argc, char * con
/* If run as root with SUDO_USER set, set sudo_user.pw to that user. */
/* XXX - causes confusion when root is not listed in sudoers */
- if (sudo_mode & (MODE_RUN | MODE_EDIT) && prev_user != NULL) {
+ if (ISSET(sudo_mode, MODE_RUN|MODE_EDIT) && prev_user != NULL) {
if (user_uid == 0 && strcmp(prev_user, "root") != 0) {
struct passwd *pw;
@@ -796,8 +796,8 @@ set_cmnd(void)
if (user_cmnd == NULL)
user_cmnd = NewArgv[0];
- if (sudo_mode & (MODE_RUN | MODE_EDIT | MODE_CHECK)) {
- if (ISSET(sudo_mode, MODE_RUN | MODE_CHECK)) {
+ if (ISSET(sudo_mode, MODE_RUN|MODE_EDIT|MODE_CHECK)) {
+ if (!ISSET(sudo_mode, MODE_EDIT)) {
if (def_secure_path && !user_is_exempt())
path = def_secure_path;
if (!set_perms(PERM_RUNAS))
@@ -835,7 +835,8 @@ set_cmnd(void)
sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
debug_return_int(-1);
}
- if (ISSET(sudo_mode, MODE_SHELL|MODE_LOGIN_SHELL)) {
+ if (ISSET(sudo_mode, MODE_SHELL|MODE_LOGIN_SHELL) &&
+ ISSET(sudo_mode, MODE_RUN)) {
/*
* When running a command via a shell, the sudo front-end
* escapes potential meta chars. We unescape non-spaces
@@ -843,10 +844,22 @@ set_cmnd(void)
*/
for (to = user_args, av = NewArgv + 1; (from = *av); av++) {
while (*from) {
- if (from[0] == '\\' && !isspace((unsigned char)from[1]))
+ if (from[0] == '\\' && from[1] != '\0' &&
+ !isspace((unsigned char)from[1])) {
from++;
+ }
+ if (size - (to - user_args) < 1) {
+ sudo_warnx(U_("internal error, %s overflow"),
+ __func__);
+ debug_return_int(NOT_FOUND_ERROR);
+ }
*to++ = *from++;
}
+ if (size - (to - user_args) < 1) {
+ sudo_warnx(U_("internal error, %s overflow"),
+ __func__);
+ debug_return_int(NOT_FOUND_ERROR);
+ }
*to++ = ' ';
}
*--to = '\0';
diff -up ./plugins/sudoers/timestamp.c.heap-buffer ./plugins/sudoers/timestamp.c
--- ./plugins/sudoers/timestamp.c.heap-buffer 2018-09-02 14:30:08.000000000 +0200
+++ ./plugins/sudoers/timestamp.c 2021-01-20 13:10:29.369619280 +0100
@@ -646,8 +646,8 @@ timestamp_lock(void *vcookie, struct pas
} else if (entry.type != TS_LOCKEXCL) {
/* Old sudo record, convert it to TS_LOCKEXCL. */
entry.type = TS_LOCKEXCL;
- memset((char *)&entry + offsetof(struct timestamp_entry, type), 0,
- nread - offsetof(struct timestamp_entry, type));
+ memset((char *)&entry + offsetof(struct timestamp_entry, flags), 0,
+ nread - offsetof(struct timestamp_entry, flags));
if (ts_write(cookie->fd, cookie->fname, &entry, 0) == -1)
debug_return_bool(false);
}
diff -up ./src/parse_args.c.heap-buffer ./src/parse_args.c
--- ./src/parse_args.c.heap-buffer 2018-08-18 16:10:25.000000000 +0200
+++ ./src/parse_args.c 2021-01-20 16:01:42.500778441 +0100
@@ -116,7 +116,10 @@ struct environment {
/*
* Default flags allowed when running a command.
*/
-#define DEFAULT_VALID_FLAGS (MODE_BACKGROUND|MODE_PRESERVE_ENV|MODE_RESET_HOME|MODE_LOGIN_SHELL|MODE_NONINTERACTIVE|MODE_SHELL)
+#define DEFAULT_VALID_FLAGS (MODE_BACKGROUND|MODE_PRESERVE_ENV|MODE_RESET_HOME|MODE_LOGIN_SHELL|MODE_NONINTERACTIVE|MODE_PRESERVE_GROUPS|MODE_SHELL)
+#define EDIT_VALID_FLAGS MODE_NONINTERACTIVE
+#define LIST_VALID_FLAGS (MODE_NONINTERACTIVE|MODE_LONG_LIST)
+#define VALIDATE_VALID_FLAGS MODE_NONINTERACTIVE
/* Option number for the --host long option due to ambiguity of the -h flag. */
#define OPT_HOSTNAME 256
@@ -260,6 +263,7 @@ parse_args(int argc, char **argv, int *n
progname = "sudoedit";
mode = MODE_EDIT;
sudo_settings[ARG_SUDOEDIT].value = "true";
+ valid_flags = EDIT_VALID_FLAGS;
}
/* Load local IP addresses and masks. */
@@ -345,7 +349,7 @@ parse_args(int argc, char **argv, int *n
usage_excl(1);
mode = MODE_EDIT;
sudo_settings[ARG_SUDOEDIT].value = "true";
- valid_flags = MODE_NONINTERACTIVE;
+ valid_flags = EDIT_VALID_FLAGS;
break;
case 'g':
if (*optarg == '\0')
@@ -355,6 +359,7 @@ parse_args(int argc, char **argv, int *n
break;
case 'H':
sudo_settings[ARG_SET_HOME].value = "true";
+ SET(flags, MODE_RESET_HOME);
break;
case 'h':
if (optarg == NULL) {
@@ -404,7 +409,7 @@ parse_args(int argc, char **argv, int *n
usage_excl(1);
}
mode = MODE_LIST;
- valid_flags = MODE_NONINTERACTIVE|MODE_LONG_LIST;
+ valid_flags = LIST_VALID_FLAGS;
break;
case 'n':
SET(flags, MODE_NONINTERACTIVE);
@@ -412,6 +417,7 @@ parse_args(int argc, char **argv, int *n
break;
case 'P':
sudo_settings[ARG_PRESERVE_GROUPS].value = "true";
+ SET(flags, MODE_PRESERVE_GROUPS);
break;
case 'p':
/* An empty prompt is allowed. */
@@ -455,7 +461,7 @@ parse_args(int argc, char **argv, int *n
if (mode && mode != MODE_VALIDATE)
usage_excl(1);
mode = MODE_VALIDATE;
- valid_flags = MODE_NONINTERACTIVE;
+ valid_flags = VALIDATE_VALID_FLAGS;
break;
case 'V':
if (mode && mode != MODE_VERSION)
@@ -482,7 +488,7 @@ parse_args(int argc, char **argv, int *n
if (!mode) {
/* Defer -k mode setting until we know whether it is a flag or not */
if (sudo_settings[ARG_IGNORE_TICKET].value != NULL) {
- if (argc == 0 && !(flags & (MODE_SHELL|MODE_LOGIN_SHELL))) {
+ if (argc == 0 && !ISSET(flags, MODE_SHELL|MODE_LOGIN_SHELL)) {
mode = MODE_INVALIDATE; /* -k by itself */
sudo_settings[ARG_IGNORE_TICKET].value = NULL;
valid_flags = 0;
@@ -545,23 +551,24 @@ parse_args(int argc, char **argv, int *n
/*
* For shell mode we need to rewrite argv
*/
- if (ISSET(mode, MODE_RUN) && ISSET(flags, MODE_SHELL)) {
+ if (ISSET(flags, MODE_SHELL|MODE_LOGIN_SHELL) && ISSET(mode, MODE_RUN)) {
char **av, *cmnd = NULL;
int ac = 1;
if (argc != 0) {
/* shell -c "command" */
char *src, *dst;
- size_t cmnd_size = (size_t) (argv[argc - 1] - argv[0]) +
- strlen(argv[argc - 1]) + 1;
+ size_t size = 0;
- cmnd = dst = reallocarray(NULL, cmnd_size, 2);
- if (cmnd == NULL)
+ for (av = argv; *av != NULL; av++)
+ size += strlen(*av) + 1;
+
+ if (size == 0 || (cmnd = reallocarray(NULL, size, 2)) == NULL)
sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
if (!gc_add(GC_PTR, cmnd))
exit(1);
- for (av = argv; *av != NULL; av++) {
+ for (dst = cmnd, av = argv; *av != NULL; av++) {
for (src = *av; *src != '\0'; src++) {
/* quote potential meta characters */
if (!isalnum((unsigned char)*src) && *src != '_' && *src != '-' && *src != '$')

12
SPECS/sudo.spec

@ -1,7 +1,7 @@ @@ -1,7 +1,7 @@
Summary: Allows restricted root access for specified users
Name: sudo
Version: 1.8.23
Release: 10%{?dist}
Release: 11%{?dist}
License: ISC
Group: Applications/System
URL: http://www.courtesan.com/sudo/
@ -74,6 +74,9 @@ Patch16: sudo-1.8.29-CVE-2019-18634-part2.patch @@ -74,6 +74,9 @@ Patch16: sudo-1.8.29-CVE-2019-18634-part2.patch
Patch17: sudo-1.8.29-expired-password-part1.patch
Patch18: sudo-1.8.29-expired-password-part2.patch

# 1917729 - EMBARGOED CVE-2021-3156 sudo: Heap-buffer overflow in argument parsing [rhel-7.9.z]
Patch19: sudo-1.8.31-CVE-2021-3156.patch

%description
Sudo (superuser do) allows a system administrator to give certain
users (or groups of users) the ability to run some (or all) commands
@ -121,6 +124,8 @@ plugins that use %{name}. @@ -121,6 +124,8 @@ plugins that use %{name}.
%patch17 -p1 -b .expired-password-part1
%patch18 -p1 -b .expired-password-part2

%patch19 -p1 -b .heap-buffer

%build
autoreconf -I m4 -fv --install

@ -256,6 +261,11 @@ rm -rf %{buildroot} @@ -256,6 +261,11 @@ rm -rf %{buildroot}
%{_mandir}/man8/sudo_plugin.8*

%changelog
* Wed Jan 20 2021 Radovan Sroka <rsroka@redhat.com> - 1.8.23-11
- RHEL 7.9.Z ERRATUM
- CVE-2021-3156
Resolves: rhbz#1917729

* Wed Mar 25 2020 Radovan Sroka <rsroka@redhat.com> - 1.8.23-10
- RHEL-7.9
- sudo allows privilege escalation with expire password

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