Samuel Cabrero
cba0a3d8f7
- Fix KDC null pointer dereference via a FAST inner body that lacks a server field; (CVE-2021-37750); (bsc#1189929); - Added patches: * 0009-Fix-KDC-null-deref-on-TGS-inner-body-null-server.patch OBS-URL: https://build.opensuse.org/request/show/915042 OBS-URL: https://build.opensuse.org/package/show/network/krb5?expand=0&rev=253
49 lines
1.5 KiB
Diff
49 lines
1.5 KiB
Diff
From 74444508aa249bf8d34865e25413c6432e7583b4 Mon Sep 17 00:00:00 2001
|
|
From: Greg Hudson <ghudson@mit.edu>
|
|
Date: Tue, 3 Aug 2021 01:15:27 -0400
|
|
Subject: [PATCH] Fix KDC null deref on TGS inner body null server
|
|
|
|
After the KDC decodes a FAST inner body, it does not check for a null
|
|
server. Prior to commit 39548a5b17bbda9eeb63625a201cfd19b9de1c5b this
|
|
would typically result in an error from krb5_unparse_name(), but with
|
|
the addition of get_local_tgt() it results in a null dereference. Add
|
|
a null check.
|
|
|
|
Reported by Joseph Sutton of Catalyst.
|
|
|
|
CVE-2021-37750:
|
|
|
|
In MIT krb5 releases 1.14 and later, an authenticated attacker can
|
|
cause a null dereference in the KDC by sending a FAST TGS request with
|
|
no server field.
|
|
|
|
ticket: 9008 (new)
|
|
tags: pullup
|
|
target_version: 1.19-next
|
|
target_version: 1.18-next
|
|
|
|
(cherry picked from commit d775c95af7606a51bf79547a94fa52ddd1cb7f49)
|
|
---
|
|
src/kdc/do_tgs_req.c | 5 +++++
|
|
1 file changed, 5 insertions(+)
|
|
|
|
diff --git a/src/kdc/do_tgs_req.c b/src/kdc/do_tgs_req.c
|
|
index 6d244ffd4..39a504ca1 100644
|
|
--- a/src/kdc/do_tgs_req.c
|
|
+++ b/src/kdc/do_tgs_req.c
|
|
@@ -207,6 +207,11 @@ process_tgs_req(krb5_kdc_req *request, krb5_data *pkt,
|
|
status = "FIND_FAST";
|
|
goto cleanup;
|
|
}
|
|
+ if (sprinc == NULL) {
|
|
+ status = "NULL_SERVER";
|
|
+ errcode = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
|
|
+ goto cleanup;
|
|
+ }
|
|
|
|
errcode = get_local_tgt(kdc_context, &sprinc->realm, header_server,
|
|
&local_tgt, &local_tgt_storage, &local_tgt_key);
|
|
--
|
|
2.33.0
|
|
|