package/sudo: fix CVE-2022-43995

Sudo 1.8.0 through 1.9.12, with the crypt() password backend, contains a
plugins/sudoers/auth/passwd.c array-out-of-bounds error that can result
in a heap-based buffer over-read. This can be triggered by arbitrary
local users with access to Sudo by entering a password of seven
characters or fewer. The impact could vary depending on the compiler and
processor architecture.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 26634490364decc24fa32f175c12c8a2d984f1d3)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/sudo/0001-Fix-CVE-2022-43995.patch

@@ -0,0 +1,53 @@
+From bd209b9f16fcd1270c13db27ae3329c677d48050 Mon Sep 17 00:00:00 2001
+From: "Todd C. Miller" <Todd.Miller@sudo.ws>
+Date: Fri, 28 Oct 2022 07:29:55 -0600
+Subject: [PATCH] Fix CVE-2022-43995, potential heap overflow for passwords < 8
+ characters. Starting with sudo 1.8.0 the plaintext password buffer is
+ dynamically sized so it is not safe to assume that it is at least 9 bytes in
+ size. Found by Hugo Lefeuvre (University of Manchester) with ConfFuzz.
+
+[Retrieved from:
+https://github.com/sudo-project/sudo/commit/bd209b9f16fcd1270c13db27ae3329c677d48050]
+Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
+---
+ plugins/sudoers/auth/passwd.c | 11 +++++------
+ 1 file changed, 5 insertions(+), 6 deletions(-)
+
+diff --git a/plugins/sudoers/auth/passwd.c b/plugins/sudoers/auth/passwd.c
+index b2046eca2..0416861e9 100644
+--- a/plugins/sudoers/auth/passwd.c
++++ b/plugins/sudoers/auth/passwd.c
+@@ -63,7 +63,7 @@ sudo_passwd_init(struct passwd *pw, sudo_auth *auth)
+ int
+ sudo_passwd_verify(struct passwd *pw, char *pass, sudo_auth *auth, struct sudo_conv_callback *callback)
+ {
+-    char sav, *epass;
++    char des_pass[9], *epass;
+     char *pw_epasswd = auth->data;
+     size_t pw_len;
+     int matched = 0;
+@@ -75,12 +75,12 @@ sudo_passwd_verify(struct passwd *pw, char *pass, sudo_auth *auth, struct sudo_c
+ 
+     /*
+      * Truncate to 8 chars if standard DES since not all crypt()'s do this.
+-     * If this turns out not to be safe we will have to use OS #ifdef's (sigh).
+      */
+-    sav = pass[8];
+     pw_len = strlen(pw_epasswd);
+-    if (pw_len == DESLEN || HAS_AGEINFO(pw_epasswd, pw_len))
+-	pass[8] = '\0';
++    if (pw_len == DESLEN || HAS_AGEINFO(pw_epasswd, pw_len)) {
++	strlcpy(des_pass, pass, sizeof(des_pass));
++	pass = des_pass;
++    }
+ 
+     /*
+      * Normal UN*X password check.
+@@ -88,7 +88,6 @@ sudo_passwd_verify(struct passwd *pw, char *pass, sudo_auth *auth, struct sudo_c
+      * only compare the first DESLEN characters in that case.
+      */
+     epass = (char *) crypt(pass, pw_epasswd);
+-    pass[8] = sav;
+     if (epass != NULL) {
+ 	if (HAS_AGEINFO(pw_epasswd, pw_len) && strlen(epass) == DESLEN)
+ 	    matched = !strncmp(pw_epasswd, epass, DESLEN);

package/sudo/sudo.mk

@@ -23,6 +23,9 @@ SUDO_CONF_OPTS = \
 	--without-interfaces \
 	--with-env-editor
 
+# 0001-Fix-CVE-2022-43995.patch
+SUDO_IGNORE_CVES += CVE-2022-43995
+
 ifeq ($(BR2_PACKAGE_LINUX_PAM),y)
 define SUDO_INSTALL_PAM_CONF
 	$(INSTALL) -D -m 0644 package/sudo/sudo.pam $(TARGET_DIR)/etc/pam.d/sudo