e71be18354
Fixes the following security issues: CVE-2020-24332 If the tcsd daemon is started with root privileges, the creation of the system.data file is prone to symlink attacks CVE-2020-24330 If the tcsd daemon is started with root privileges, it fails to drop the root gid after it is no longer needed CVE-2020-24331 If the tcsd daemon is started with root privileges, the tss user has read and write access to the /etc/tcsd.conf file For details, see the advisory: https://www.openwall.com/lists/oss-security/2020/05/20/3 Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
91 lines
3.0 KiB
Diff
91 lines
3.0 KiB
Diff
From e74dd1d96753b0538192143adf58d04fcd3b242b Mon Sep 17 00:00:00 2001
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From: Matthias Gerstner <mgerstner@suse.de>
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Date: Fri, 14 Aug 2020 22:14:36 -0700
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Subject: [PATCH] Correct multiple security issues that are present if the tcsd
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is started by root instead of the tss user.
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Patch fixes the following 3 CVEs:
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CVE-2020-24332
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If the tcsd daemon is started with root privileges,
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the creation of the system.data file is prone to symlink attacks
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CVE-2020-24330
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If the tcsd daemon is started with root privileges,
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it fails to drop the root gid after it is no longer needed
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CVE-2020-24331
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If the tcsd daemon is started with root privileges,
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the tss user has read and write access to the /etc/tcsd.conf file
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Authored-by: Matthias Gerstner <mgerstner@suse.de>
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Signed-off-by: Debora Velarde Babb <debora@linux.ibm.com>
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Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
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---
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src/tcs/ps/tcsps.c | 2 +-
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src/tcsd/svrside.c | 1 +
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src/tcsd/tcsd_conf.c | 10 +++++-----
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3 files changed, 7 insertions(+), 6 deletions(-)
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diff --git a/src/tcs/ps/tcsps.c b/src/tcs/ps/tcsps.c
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index e47154b..85d45a9 100644
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--- a/src/tcs/ps/tcsps.c
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+++ b/src/tcs/ps/tcsps.c
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@@ -72,7 +72,7 @@ get_file()
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}
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/* open and lock the file */
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- system_ps_fd = open(tcsd_options.system_ps_file, O_CREAT|O_RDWR, 0600);
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+ system_ps_fd = open(tcsd_options.system_ps_file, O_CREAT|O_RDWR|O_NOFOLLOW, 0600);
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if (system_ps_fd < 0) {
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LogError("system PS: open() of %s failed: %s",
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tcsd_options.system_ps_file, strerror(errno));
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diff --git a/src/tcsd/svrside.c b/src/tcsd/svrside.c
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index 1ae1636..1c12ff3 100644
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--- a/src/tcsd/svrside.c
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+++ b/src/tcsd/svrside.c
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@@ -473,6 +473,7 @@ main(int argc, char **argv)
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}
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return TCSERR(TSS_E_INTERNAL_ERROR);
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}
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+ setgid(pwd->pw_gid);
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setuid(pwd->pw_uid);
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#endif
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#endif
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diff --git a/src/tcsd/tcsd_conf.c b/src/tcsd/tcsd_conf.c
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index a31503d..ea8ea13 100644
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--- a/src/tcsd/tcsd_conf.c
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+++ b/src/tcsd/tcsd_conf.c
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@@ -743,7 +743,7 @@ conf_file_init(struct tcsd_config *conf)
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#ifndef SOLARIS
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struct group *grp;
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struct passwd *pw;
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- mode_t mode = (S_IRUSR|S_IWUSR);
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+ mode_t mode = (S_IRUSR|S_IWUSR|S_IRGRP);
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#endif /* SOLARIS */
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TSS_RESULT result;
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@@ -798,15 +798,15 @@ conf_file_init(struct tcsd_config *conf)
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}
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/* make sure user/group TSS owns the conf file */
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- if (pw->pw_uid != stat_buf.st_uid || grp->gr_gid != stat_buf.st_gid) {
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+ if (stat_buf.st_uid != 0 || grp->gr_gid != stat_buf.st_gid) {
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LogError("TCSD config file (%s) must be user/group %s/%s", tcsd_config_file,
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- TSS_USER_NAME, TSS_GROUP_NAME);
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+ "root", TSS_GROUP_NAME);
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return TCSERR(TSS_E_INTERNAL_ERROR);
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}
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- /* make sure only the tss user can manipulate the config file */
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+ /* make sure only the tss user can read (but not manipulate) the config file */
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if (((stat_buf.st_mode & 0777) ^ mode) != 0) {
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- LogError("TCSD config file (%s) must be mode 0600", tcsd_config_file);
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+ LogError("TCSD config file (%s) must be mode 0640", tcsd_config_file);
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return TCSERR(TSS_E_INTERNAL_ERROR);
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}
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#endif /* SOLARIS */
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--
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2.20.1
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