From 32140218a8026016687c7017a82113b0b45cf1a6 Mon Sep 17 00:00:00 2001 From: Yi Zhao Date: Fri, 10 Sep 2021 11:52:48 +0800 Subject: krb5: fix CVE-2021-37750 CVE-2021-37750: The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.5 and 1.19.x before 1.19.3 has a NULL pointer dereference in kdc/do_tgs_req.c via a FAST inner body that lacks a server field. References: https://nvd.nist.gov/vuln/detail/CVE-2021-37750 Patches from: https://github.com/krb5/krb5/commit/d775c95af7606a51bf79547a94fa52ddd1cb7f49 Signed-off-by: Yi Zhao Signed-off-by: Khem Raj --- .../krb5/krb5/CVE-2021-37750.patch | 53 ++++++++++++++++++++++ meta-oe/recipes-connectivity/krb5/krb5_1.17.2.bb | 1 + 2 files changed, 54 insertions(+) create mode 100644 meta-oe/recipes-connectivity/krb5/krb5/CVE-2021-37750.patch diff --git a/meta-oe/recipes-connectivity/krb5/krb5/CVE-2021-37750.patch b/meta-oe/recipes-connectivity/krb5/krb5/CVE-2021-37750.patch new file mode 100644 index 0000000000..c67bca32e7 --- /dev/null +++ b/meta-oe/recipes-connectivity/krb5/krb5/CVE-2021-37750.patch @@ -0,0 +1,53 @@ +From b3999be7ab59a5af4b2f1042ce0d6b03ecb17d4e Mon Sep 17 00:00:00 2001 +From: Greg Hudson +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 + +CVE: CVE-2021-37750 + +Upstream-Status: Backport +[https://github.com/krb5/krb5/commit/d775c95af7606a51bf79547a94fa52ddd1cb7f49] + +Signed-off-by: Yi Zhao +--- + 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 587342a..622b48f 100644 +--- a/src/kdc/do_tgs_req.c ++++ b/src/kdc/do_tgs_req.c +@@ -201,6 +201,11 @@ 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); +-- +2.17.1 + diff --git a/meta-oe/recipes-connectivity/krb5/krb5_1.17.2.bb b/meta-oe/recipes-connectivity/krb5/krb5_1.17.2.bb index 197c1e096b..6e0b2fdacb 100644 --- a/meta-oe/recipes-connectivity/krb5/krb5_1.17.2.bb +++ b/meta-oe/recipes-connectivity/krb5/krb5_1.17.2.bb @@ -31,6 +31,7 @@ SRC_URI = "http://web.mit.edu/kerberos/dist/${BPN}/${SHRT_VER}/${BP}.tar.gz \ file://krb5-kdc.service \ file://krb5-admin-server.service \ file://CVE-2021-36222.patch;striplevel=2 \ + file://CVE-2021-37750.patch;striplevel=2 \ " SRC_URI[md5sum] = "aa4337fffa3b61f22dbd0167f708818f" SRC_URI[sha256sum] = "1a4bba94df92f6d39a197a10687653e8bfbc9a2076e129f6eb92766974f86134" -- cgit 1.2.3-korg