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56 lines
1.8 KiB
56 lines
1.8 KiB
From 9dcead87e6d7f66d34e7a56d11a30daca367dffb Mon Sep 17 00:00:00 2001 |
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From: "Dmitry V. Levin" <ldv@altlinux.org> |
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Date: Wed, 26 Mar 2014 22:17:23 +0000 |
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Subject: [PATCH] pam_timestamp: fix potential directory traversal issue |
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(ticket #27) |
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pam_timestamp uses values of PAM_RUSER and PAM_TTY as components of |
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the timestamp pathname it creates, so extra care should be taken to |
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avoid potential directory traversal issues. |
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* modules/pam_timestamp/pam_timestamp.c (check_tty): Treat |
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"." and ".." tty values as invalid. |
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(get_ruser): Treat "." and ".." ruser values, as well as any ruser |
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value containing '/', as invalid. |
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Fixes CVE-2014-2583. |
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Reported-by: Sebastian Krahmer <krahmer@suse.de> |
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--- |
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modules/pam_timestamp/pam_timestamp.c | 13 ++++++++++++- |
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1 file changed, 12 insertions(+), 1 deletion(-) |
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diff --git a/modules/pam_timestamp/pam_timestamp.c b/modules/pam_timestamp/pam_timestamp.c |
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index 5193733..b3f08b1 100644 |
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--- a/modules/pam_timestamp/pam_timestamp.c |
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+++ b/modules/pam_timestamp/pam_timestamp.c |
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@@ -158,7 +158,7 @@ check_tty(const char *tty) |
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tty = strrchr(tty, '/') + 1; |
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} |
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/* Make sure the tty wasn't actually a directory (no basename). */ |
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- if (strlen(tty) == 0) { |
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+ if (!strlen(tty) || !strcmp(tty, ".") || !strcmp(tty, "..")) { |
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return NULL; |
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} |
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return tty; |
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@@ -243,6 +243,17 @@ get_ruser(pam_handle_t *pamh, char *ruserbuf, size_t ruserbuflen) |
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if (pwd != NULL) { |
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ruser = pwd->pw_name; |
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} |
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+ } else { |
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+ /* |
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+ * This ruser is used by format_timestamp_name as a component |
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+ * of constructed timestamp pathname, so ".", "..", and '/' |
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+ * are disallowed to avoid potential path traversal issues. |
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+ */ |
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+ if (!strcmp(ruser, ".") || |
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+ !strcmp(ruser, "..") || |
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+ strchr(ruser, '/')) { |
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+ ruser = NULL; |
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+ } |
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} |
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if (ruser == NULL || strlen(ruser) >= ruserbuflen) { |
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*ruserbuf = '\0'; |
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-- |
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1.8.3.1 |
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