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| author | Dmitry V. Levin <ldv@altlinux.org> | 2014-03-26 22:17:23 +0000 |
|---|---|---|
| committer | Dmitry V. Levin <ldv@altlinux.org> | 2014-03-26 22:17:23 +0000 |
| commit | 9dcead87e6d7f66d34e7a56d11a30daca367dffb (patch) | |
| tree | 27a38640b5de24d1cd42eff5fcdd80bbc2c2b5c1 /modules/pam_timestamp/pam_timestamp.c | |
| parent | d332be7fa933f5424abee6c7e385f0de174603d2 (diff) | |
| download | pam-9dcead87e6d7f66d34e7a56d11a30daca367dffb.tar.gz pam-9dcead87e6d7f66d34e7a56d11a30daca367dffb.tar.bz2 pam-9dcead87e6d7f66d34e7a56d11a30daca367dffb.zip | |
pam_timestamp: fix potential directory traversal issue (ticket #27)
pam_timestamp uses values of PAM_RUSER and PAM_TTY as components of
the timestamp pathname it creates, so extra care should be taken to
avoid potential directory traversal issues.
* modules/pam_timestamp/pam_timestamp.c (check_tty): Treat
"." and ".." tty values as invalid.
(get_ruser): Treat "." and ".." ruser values, as well as any ruser
value containing '/', as invalid.
Fixes CVE-2014-2583.
Reported-by: Sebastian Krahmer <krahmer@suse.de>
Diffstat (limited to 'modules/pam_timestamp/pam_timestamp.c')
| -rw-r--r-- | modules/pam_timestamp/pam_timestamp.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/modules/pam_timestamp/pam_timestamp.c b/modules/pam_timestamp/pam_timestamp.c index 51937333..b3f08b1f 100644 --- a/modules/pam_timestamp/pam_timestamp.c +++ b/modules/pam_timestamp/pam_timestamp.c @@ -158,7 +158,7 @@ check_tty(const char *tty) tty = strrchr(tty, '/') + 1; } /* Make sure the tty wasn't actually a directory (no basename). */ - if (strlen(tty) == 0) { + if (!strlen(tty) || !strcmp(tty, ".") || !strcmp(tty, "..")) { return NULL; } return tty; @@ -243,6 +243,17 @@ get_ruser(pam_handle_t *pamh, char *ruserbuf, size_t ruserbuflen) if (pwd != NULL) { ruser = pwd->pw_name; } + } else { + /* + * This ruser is used by format_timestamp_name as a component + * of constructed timestamp pathname, so ".", "..", and '/' + * are disallowed to avoid potential path traversal issues. + */ + if (!strcmp(ruser, ".") || + !strcmp(ruser, "..") || + strchr(ruser, '/')) { + ruser = NULL; + } } if (ruser == NULL || strlen(ruser) >= ruserbuflen) { *ruserbuf = '\0'; |