krb5: Fix CVE-2023-36054

lib/kadm5/kadm_rpc_xdr.c in MIT Kerberos 5 (aka krb5) before 1.20.2
and 1.21.x before 1.21.1 frees an uninitialized pointer. A remote
authenticated user can trigger a kadmind crash. This occurs because
_xdr_kadm5_principal_ent_rec does not validate the relationship
between n_key_data and the key_data array count.

References:
https://nvd.nist.gov/vuln/detail/CVE-2023-36054

Signed-off-by: Soumya Sambu <soumya.sambu@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
This commit is contained in:
Soumya Sambu 2023-08-25 07:38:26 +00:00 committed by Armin Kuster
parent 7c127728e7
commit 39d15cf5cb
2 changed files with 69 additions and 0 deletions

View File

@ -0,0 +1,68 @@
From ef08b09c9459551aabbe7924fb176f1583053cdd Mon Sep 17 00:00:00 2001
From: Greg Hudson <ghudson@mit.edu>
Date: Mon, 21 Aug 2023 03:08:15 +0000
Subject: [PATCH] Ensure array count consistency in kadm5 RPC
In _xdr_kadm5_principal_ent_rec(), ensure that n_key_data matches the
key_data array count when decoding. Otherwise when the structure is
later freed, xdr_array() could iterate over the wrong number of
elements, either leaking some memory or freeing uninitialized
pointers. Reported by Robert Morris.
CVE: CVE-2023-36054
An authenticated attacker can cause a kadmind process to crash by
freeing uninitialized pointers. Remote code execution is unlikely.
An attacker with control of a kadmin server can cause a kadmin client
to crash by freeing uninitialized pointers.
ticket: 9099 (new)
tags: pullup
target_version: 1.21-next
target_version: 1.20-next
Upstream-Status: Backport [https://github.com/krb5/krb5/commit/ef08b09c9459551aabbe7924fb176f1583053cdd]
Signed-off-by: Soumya Sambu <soumya.sambu@windriver.com>
---
src/lib/kadm5/kadm_rpc_xdr.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/src/lib/kadm5/kadm_rpc_xdr.c b/src/lib/kadm5/kadm_rpc_xdr.c
index 2892d41..94b1ce8 100644
--- a/src/lib/kadm5/kadm_rpc_xdr.c
+++ b/src/lib/kadm5/kadm_rpc_xdr.c
@@ -390,6 +390,7 @@ _xdr_kadm5_principal_ent_rec(XDR *xdrs, kadm5_principal_ent_rec *objp,
int v)
{
unsigned int n;
+ bool_t r;
if (!xdr_krb5_principal(xdrs, &objp->principal)) {
return (FALSE);
@@ -443,6 +444,9 @@ _xdr_kadm5_principal_ent_rec(XDR *xdrs, kadm5_principal_ent_rec *objp,
if (!xdr_krb5_int16(xdrs, &objp->n_key_data)) {
return (FALSE);
}
+ if (xdrs->x_op == XDR_DECODE && objp->n_key_data < 0) {
+ return (FALSE);
+ }
if (!xdr_krb5_int16(xdrs, &objp->n_tl_data)) {
return (FALSE);
}
@@ -451,9 +455,10 @@ _xdr_kadm5_principal_ent_rec(XDR *xdrs, kadm5_principal_ent_rec *objp,
return FALSE;
}
n = objp->n_key_data;
- if (!xdr_array(xdrs, (caddr_t *) &objp->key_data,
- &n, ~0, sizeof(krb5_key_data),
- xdr_krb5_key_data_nocontents)) {
+ r = xdr_array(xdrs, (caddr_t *) &objp->key_data, &n, objp->n_key_data,
+ sizeof(krb5_key_data), xdr_krb5_key_data_nocontents);
+ objp->n_key_data = n;
+ if (!r) {
return (FALSE);
}
--
2.40.0

View File

@ -33,6 +33,7 @@ SRC_URI = "http://web.mit.edu/kerberos/dist/${BPN}/${SHRT_VER}/${BP}.tar.gz \
file://CVE-2021-36222.patch;striplevel=2 \
file://CVE-2021-37750.patch;striplevel=2 \
file://CVE-2022-42898.patch;striplevel=2 \
file://CVE-2023-36054.patch;striplevel=2 \
"
SRC_URI[md5sum] = "aa4337fffa3b61f22dbd0167f708818f"
SRC_URI[sha256sum] = "1a4bba94df92f6d39a197a10687653e8bfbc9a2076e129f6eb92766974f86134"