diff --git a/SOURCES/sudo-1.8.31-CVE-2021-3156.patch b/SOURCES/sudo-1.8.31-CVE-2021-3156.patch
new file mode 100644
index 0000000..ba63838
--- /dev/null
+++ b/SOURCES/sudo-1.8.31-CVE-2021-3156.patch
@@ -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 != '$')
diff --git a/SPECS/sudo.spec b/SPECS/sudo.spec
index 7dfc84d..a9d8e28 100644
--- a/SPECS/sudo.spec
+++ b/SPECS/sudo.spec
@@ -1,7 +1,7 @@
Summary: Allows restricted root access for specified users
Name: sudo
Version: 1.8.23
-Release: 10%{?dist}
+Release: 10%{?dist}.1
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
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}.
%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}
%{_mandir}/man8/sudo_plugin.8*
%changelog
+* Wed Jan 20 2021 Radovan Sroka <rsroka@redhat.com> - 1.8.23-10.1
+- 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