From: Kai Kang <[email protected]> Backport patch to fix CVE-2021-3621.
CVE: CVE-2021-3621 Signed-off-by: Kai Kang <[email protected]> --- .../sssd/files/CVE-2021-3621.patch | 291 ++++++++++++++++++ recipes-security/sssd/sssd_1.16.5.bb | 1 + 2 files changed, 292 insertions(+) create mode 100644 recipes-security/sssd/files/CVE-2021-3621.patch diff --git a/recipes-security/sssd/files/CVE-2021-3621.patch b/recipes-security/sssd/files/CVE-2021-3621.patch new file mode 100644 index 0000000..3d2c707 --- /dev/null +++ b/recipes-security/sssd/files/CVE-2021-3621.patch @@ -0,0 +1,291 @@ +Backport patch to fix CVE-2021-3621. + +Upstream-Status: Backport [https://github.com/SSSD/sssd/commit/b4b3267] +CVE: CVE-2021-3621 + +Signed-off-by: Kai Kang <[email protected]> + +From b4b32677a886bc26d60ce0171505aa3ab0c82c8a Mon Sep 17 00:00:00 2001 +From: Alexey Tikhonov <[email protected]> +Date: Fri, 30 Jul 2021 19:05:31 +0200 +Subject: [PATCH] TOOLS: replace system() with execvp() to avoid execution of + user supplied command +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +:relnote: A flaw was found in SSSD, where the sssctl command was +vulnerable to shell command injection via the logs-fetch and +cache-expire subcommands. This flaw allows an attacker to trick +the root user into running a specially crafted sssctl command, +such as via sudo, to gain root access. The highest threat from this +vulnerability is to confidentiality, integrity, as well as system +availability. +This patch fixes a flaw by replacing system() with execvp(). + +:fixes: CVE-2021-3621 + +Reviewed-by: Pavel Březina <[email protected]> +--- + src/tools/sssctl/sssctl.c | 40 +++++++++++++++++------- + src/tools/sssctl/sssctl.h | 2 +- + src/tools/sssctl/sssctl_data.c | 57 +++++++++++----------------------- + src/tools/sssctl/sssctl_logs.c | 31 ++++++++++++++---- + 4 files changed, 73 insertions(+), 57 deletions(-) + +diff --git a/src/tools/sssctl/sssctl.c b/src/tools/sssctl/sssctl.c +index afaa84bc0..403c89c35 100644 +--- a/src/tools/sssctl/sssctl.c ++++ b/src/tools/sssctl/sssctl.c +@@ -97,22 +97,37 @@ sssctl_prompt(const char *message, + return SSSCTL_PROMPT_ERROR; + } + +-errno_t sssctl_run_command(const char *command) ++errno_t sssctl_run_command(const char *const argv[]) + { + int ret; ++ int wstatus; + +- DEBUG(SSSDBG_TRACE_FUNC, "Running %s\n", command); ++ DEBUG(SSSDBG_TRACE_FUNC, "Running '%s'\n", argv[0]); + +- ret = system(command); ++ ret = fork(); + if (ret == -1) { +- DEBUG(SSSDBG_CRIT_FAILURE, "Unable to execute %s\n", command); + fprintf(stderr, _("Error while executing external command\n")); + return EFAULT; +- } else if (WEXITSTATUS(ret) != 0) { +- DEBUG(SSSDBG_CRIT_FAILURE, "Command %s failed with [%d]\n", +- command, WEXITSTATUS(ret)); ++ } ++ ++ if (ret == 0) { ++ /* cast is safe - see ++ https://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html ++ "The statement about argv[] and envp[] being constants ... " ++ */ ++ execvp(argv[0], discard_const_p(char * const, argv)); + fprintf(stderr, _("Error while executing external command\n")); +- return EIO; ++ _exit(1); ++ } else { ++ if (waitpid(ret, &wstatus, 0) == -1) { ++ fprintf(stderr, ++ _("Error while executing external command '%s'\n"), argv[0]); ++ return EFAULT; ++ } else if (WEXITSTATUS(wstatus) != 0) { ++ fprintf(stderr, ++ _("Command '%s' failed with [%d]\n"), argv[0], WEXITSTATUS(wstatus)); ++ return EIO; ++ } + } + + return EOK; +@@ -132,11 +147,14 @@ static errno_t sssctl_manage_service(enum sssctl_svc_action action) + #elif defined(HAVE_SERVICE) + switch (action) { + case SSSCTL_SVC_START: +- return sssctl_run_command(SERVICE_PATH" sssd start"); ++ return sssctl_run_command( ++ (const char *[]){SERVICE_PATH, "sssd", "start", NULL}); + case SSSCTL_SVC_STOP: +- return sssctl_run_command(SERVICE_PATH" sssd stop"); ++ return sssctl_run_command( ++ (const char *[]){SERVICE_PATH, "sssd", "stop", NULL}); + case SSSCTL_SVC_RESTART: +- return sssctl_run_command(SERVICE_PATH" sssd restart"); ++ return sssctl_run_command( ++ (const char *[]){SERVICE_PATH, "sssd", "restart", NULL}); + } + #endif + +diff --git a/src/tools/sssctl/sssctl.h b/src/tools/sssctl/sssctl.h +index 70fc19eff..71f798b2a 100644 +--- a/src/tools/sssctl/sssctl.h ++++ b/src/tools/sssctl/sssctl.h +@@ -42,7 +42,7 @@ enum sssctl_prompt_result + sssctl_prompt(const char *message, + enum sssctl_prompt_result defval); + +-errno_t sssctl_run_command(const char *command); ++errno_t sssctl_run_command(const char *const argv[]); /* argv[0] - command */ + bool sssctl_start_sssd(bool force); + bool sssctl_stop_sssd(bool force); + bool sssctl_restart_sssd(bool force); +diff --git a/src/tools/sssctl/sssctl_data.c b/src/tools/sssctl/sssctl_data.c +index cc46cafbf..8a042664c 100644 +--- a/src/tools/sssctl/sssctl_data.c ++++ b/src/tools/sssctl/sssctl_data.c +@@ -105,15 +105,15 @@ static errno_t sssctl_backup(bool force) + } + } + +- ret = sssctl_run_command("sss_override user-export " +- SSS_BACKUP_USER_OVERRIDES); ++ ret = sssctl_run_command((const char *[]){"sss_override", "user-export", ++ SSS_BACKUP_USER_OVERRIDES, NULL}); + if (ret != EOK) { + fprintf(stderr, _("Unable to export user overrides\n")); + return ret; + } + +- ret = sssctl_run_command("sss_override group-export " +- SSS_BACKUP_GROUP_OVERRIDES); ++ ret = sssctl_run_command((const char *[]){"sss_override", "group-export", ++ SSS_BACKUP_GROUP_OVERRIDES, NULL}); + if (ret != EOK) { + fprintf(stderr, _("Unable to export group overrides\n")); + return ret; +@@ -158,8 +158,8 @@ static errno_t sssctl_restore(bool force_start, bool force_restart) + } + + if (sssctl_backup_file_exists(SSS_BACKUP_USER_OVERRIDES)) { +- ret = sssctl_run_command("sss_override user-import " +- SSS_BACKUP_USER_OVERRIDES); ++ ret = sssctl_run_command((const char *[]){"sss_override", "user-import", ++ SSS_BACKUP_USER_OVERRIDES, NULL}); + if (ret != EOK) { + fprintf(stderr, _("Unable to import user overrides\n")); + return ret; +@@ -167,8 +167,8 @@ static errno_t sssctl_restore(bool force_start, bool force_restart) + } + + if (sssctl_backup_file_exists(SSS_BACKUP_USER_OVERRIDES)) { +- ret = sssctl_run_command("sss_override group-import " +- SSS_BACKUP_GROUP_OVERRIDES); ++ ret = sssctl_run_command((const char *[]){"sss_override", "group-import", ++ SSS_BACKUP_GROUP_OVERRIDES, NULL}); + if (ret != EOK) { + fprintf(stderr, _("Unable to import group overrides\n")); + return ret; +@@ -296,40 +296,19 @@ errno_t sssctl_cache_expire(struct sss_cmdline *cmdline, + void *pvt) + { + errno_t ret; +- char *cmd_args = NULL; +- const char *cachecmd = SSS_CACHE; +- char *cmd = NULL; +- int i; +- +- if (cmdline->argc == 0) { +- ret = sssctl_run_command(cachecmd); +- goto done; +- } + +- cmd_args = talloc_strdup(tool_ctx, ""); +- if (cmd_args == NULL) { +- ret = ENOMEM; +- goto done; ++ const char **args = talloc_array_size(tool_ctx, ++ sizeof(char *), ++ cmdline->argc + 2); ++ if (!args) { ++ return ENOMEM; + } ++ memcpy(&args[1], cmdline->argv, sizeof(char *) * cmdline->argc); ++ args[0] = SSS_CACHE; ++ args[cmdline->argc + 1] = NULL; + +- for (i = 0; i < cmdline->argc; i++) { +- cmd_args = talloc_strdup_append(cmd_args, cmdline->argv[i]); +- if (i != cmdline->argc - 1) { +- cmd_args = talloc_strdup_append(cmd_args, " "); +- } +- } +- +- cmd = talloc_asprintf(tool_ctx, "%s %s", cachecmd, cmd_args); +- if (cmd == NULL) { +- ret = ENOMEM; +- goto done; +- } +- +- ret = sssctl_run_command(cmd); +- +-done: +- talloc_free(cmd_args); +- talloc_free(cmd); ++ ret = sssctl_run_command(args); + ++ talloc_free(args); + return ret; + } +diff --git a/src/tools/sssctl/sssctl_logs.c b/src/tools/sssctl/sssctl_logs.c +index aca988c05..c85cc7a4b 100644 +--- a/src/tools/sssctl/sssctl_logs.c ++++ b/src/tools/sssctl/sssctl_logs.c +@@ -32,6 +32,7 @@ + #include <popt.h> + #include <stdio.h> + #include <signal.h> ++#include <glob.h> + + #include "util/util.h" + #include "tools/common/sss_process.h" +@@ -231,6 +232,7 @@ errno_t sssctl_logs_remove(struct sss_cmdline *cmdline, + { + struct sssctl_logs_opts opts = {0}; + errno_t ret; ++ glob_t globbuf; + + /* Parse command line. */ + struct poptOption options[] = { +@@ -254,8 +256,19 @@ errno_t sssctl_logs_remove(struct sss_cmdline *cmdline, + + sss_signal(SIGHUP); + } else { ++ globbuf.gl_offs = 4; ++ ret = glob(LOG_PATH"/*.log", GLOB_ERR|GLOB_DOOFFS, NULL, &globbuf); ++ if (ret != 0) { ++ DEBUG(SSSDBG_CRIT_FAILURE, "Unable to expand log files list\n"); ++ return ret; ++ } ++ globbuf.gl_pathv[0] = discard_const_p(char, "truncate"); ++ globbuf.gl_pathv[2] = discard_const_p(char, "--size"); ++ globbuf.gl_pathv[3] = discard_const_p(char, "0"); ++ + printf(_("Truncating log files...\n")); +- ret = sssctl_run_command("truncate --size 0 " LOG_FILES); ++ ret = sssctl_run_command((const char * const*)globbuf.gl_pathv); ++ globfree(&globbuf); + if (ret != EOK) { + fprintf(stderr, _("Unable to truncate log files\n")); + return ret; +@@ -270,8 +283,8 @@ errno_t sssctl_logs_fetch(struct sss_cmdline *cmdline, + void *pvt) + { + const char *file; +- const char *cmd; + errno_t ret; ++ glob_t globbuf; + + /* Parse command line. */ + ret = sss_tool_popt_ex(cmdline, NULL, SSS_TOOL_OPT_OPTIONAL, NULL, NULL, +@@ -281,13 +294,19 @@ errno_t sssctl_logs_fetch(struct sss_cmdline *cmdline, + return ret; + } + +- cmd = talloc_asprintf(tool_ctx, "tar -czf %s %s", file, LOG_FILES); +- if (cmd == NULL) { +- fprintf(stderr, _("Out of memory!")); ++ globbuf.gl_offs = 3; ++ ret = glob(LOG_PATH"/*.log", GLOB_ERR|GLOB_DOOFFS, NULL, &globbuf); ++ if (ret != 0) { ++ DEBUG(SSSDBG_CRIT_FAILURE, "Unable to expand log files list\n"); ++ return ret; + } ++ globbuf.gl_pathv[0] = discard_const_p(char, "tar"); ++ globbuf.gl_pathv[1] = discard_const_p(char, "-czf"); ++ globbuf.gl_pathv[2] = discard_const_p(char, file); + + printf(_("Archiving log files into %s...\n"), file); +- ret = sssctl_run_command(cmd); ++ ret = sssctl_run_command((const char * const*)globbuf.gl_pathv); ++ globfree(&globbuf); + if (ret != EOK) { + fprintf(stderr, _("Unable to archive log files\n")); + return ret; +-- +2.33.0 + diff --git a/recipes-security/sssd/sssd_1.16.5.bb b/recipes-security/sssd/sssd_1.16.5.bb index 9784ec7..02d0837 100644 --- a/recipes-security/sssd/sssd_1.16.5.bb +++ b/recipes-security/sssd/sssd_1.16.5.bb @@ -22,6 +22,7 @@ SRC_URI = "https://releases.pagure.org/SSSD/${BPN}/${BP}.tar.gz \ file://0001-build-Don-t-use-AC_CHECK_FILE-when-building-manpages.patch \ file://0001-nss-Collision-with-external-nss-symbol.patch \ file://0002-Provide-missing-defines-which-otherwise-are-availabl.patch \ + file://CVE-2021-3621.patch \ " SRC_URI[sha256sum] = "2e1a7bf036b583f686d35164f2d79bdf4857b98f51fe8b0d17aa0fa756e4d0c0" -- 2.17.1
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