openssl: fix CVE-2023-464 and CVE-2023-465

Apply two patches fixing low-severity vulnerabilities related to
certificate policies validation:

- Excessive Resource Usage Verifying X.509 Policy Constraints
  (CVE-2023-0464)
  Severity: Low
  A security vulnerability has been identified in all supported versions
  of OpenSSL related to the verification of X.509 certificate chains
  that include policy constraints.  Attackers may be able to exploit
  this vulnerability by creating a malicious certificate chain that
  triggers exponential use of computational resources, leading to a
  denial-of-service (DoS) attack on affected systems.
  Policy processing is disabled by default but can be enabled by passing
  the `-policy' argument to the command line utilities or by calling the
  `X509_VERIFY_PARAM_set1_policies()' function.

- Invalid certificate policies in leaf certificates are silently ignored
  (CVE-2023-0465)
  Severity: Low
  Applications that use a non-default option when verifying certificates
  may be vulnerable to an attack from a malicious CA to circumvent
  certain checks.
  Invalid certificate policies in leaf certificates are silently ignored
  by OpenSSL and other certificate policy checks are skipped for that
  certificate.  A malicious CA could use this to deliberately assert
  invalid certificate policies in order to circumvent policy checking on
  the certificate altogether.
  Policy processing is disabled by default but can be enabled by passing
  the `-policy' argument to the command line utilities or by calling the
  `X509_VERIFY_PARAM_set1_policies()' function.

Note: OpenSSL also released a fix for low-severity security advisory
CVE-2023-466.  It is not included here because the fix only changes the
documentation, which is not built nor included in any OpenWrt package.

Due to the low-severity of these issues, there will be not be an
immediate new release of OpenSSL.

Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>
This commit is contained in:
Eneas U de Queiroz 2023-04-04 15:39:56 -03:00
parent 34d2883b9d
commit f8282da11e
No known key found for this signature in database
GPG Key ID: A1FE5A85EFAE657D
3 changed files with 263 additions and 1 deletions

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@ -11,7 +11,7 @@ PKG_NAME:=openssl
PKG_BASE:=1.1.1
PKG_BUGFIX:=t
PKG_VERSION:=$(PKG_BASE)$(PKG_BUGFIX)
PKG_RELEASE:=1
PKG_RELEASE:=2
PKG_USE_MIPS16:=0
ENGINES_DIR=engines-1.1

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@ -0,0 +1,214 @@
From 879f7080d7e141f415c79eaa3a8ac4a3dad0348b Mon Sep 17 00:00:00 2001
From: Pauli <pauli@openssl.org>
Date: Wed, 8 Mar 2023 15:28:20 +1100
Subject: [PATCH] x509: excessive resource use verifying policy constraints
A security vulnerability has been identified in all supported versions
of OpenSSL related to the verification of X.509 certificate chains
that include policy constraints. Attackers may be able to exploit this
vulnerability by creating a malicious certificate chain that triggers
exponential use of computational resources, leading to a denial-of-service
(DoS) attack on affected systems.
Fixes CVE-2023-0464
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/20569)
diff --git a/crypto/x509v3/pcy_local.h b/crypto/x509v3/pcy_local.h
index 5daf78de45..344aa06765 100644
--- a/crypto/x509v3/pcy_local.h
+++ b/crypto/x509v3/pcy_local.h
@@ -111,6 +111,11 @@ struct X509_POLICY_LEVEL_st {
};
struct X509_POLICY_TREE_st {
+ /* The number of nodes in the tree */
+ size_t node_count;
+ /* The maximum number of nodes in the tree */
+ size_t node_maximum;
+
/* This is the tree 'level' data */
X509_POLICY_LEVEL *levels;
int nlevel;
@@ -159,7 +164,8 @@ X509_POLICY_NODE *tree_find_sk(STACK_OF(X509_POLICY_NODE) *sk,
X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
X509_POLICY_DATA *data,
X509_POLICY_NODE *parent,
- X509_POLICY_TREE *tree);
+ X509_POLICY_TREE *tree,
+ int extra_data);
void policy_node_free(X509_POLICY_NODE *node);
int policy_node_match(const X509_POLICY_LEVEL *lvl,
const X509_POLICY_NODE *node, const ASN1_OBJECT *oid);
diff --git a/crypto/x509v3/pcy_node.c b/crypto/x509v3/pcy_node.c
index e2d7b15322..d574fb9d66 100644
--- a/crypto/x509v3/pcy_node.c
+++ b/crypto/x509v3/pcy_node.c
@@ -59,10 +59,15 @@ X509_POLICY_NODE *level_find_node(const X509_POLICY_LEVEL *level,
X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
X509_POLICY_DATA *data,
X509_POLICY_NODE *parent,
- X509_POLICY_TREE *tree)
+ X509_POLICY_TREE *tree,
+ int extra_data)
{
X509_POLICY_NODE *node;
+ /* Verify that the tree isn't too large. This mitigates CVE-2023-0464 */
+ if (tree->node_maximum > 0 && tree->node_count >= tree->node_maximum)
+ return NULL;
+
node = OPENSSL_zalloc(sizeof(*node));
if (node == NULL) {
X509V3err(X509V3_F_LEVEL_ADD_NODE, ERR_R_MALLOC_FAILURE);
@@ -70,7 +75,7 @@ X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
}
node->data = data;
node->parent = parent;
- if (level) {
+ if (level != NULL) {
if (OBJ_obj2nid(data->valid_policy) == NID_any_policy) {
if (level->anyPolicy)
goto node_error;
@@ -90,7 +95,7 @@ X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
}
}
- if (tree) {
+ if (extra_data) {
if (tree->extra_data == NULL)
tree->extra_data = sk_X509_POLICY_DATA_new_null();
if (tree->extra_data == NULL){
@@ -103,6 +108,7 @@ X509_POLICY_NODE *level_add_node(X509_POLICY_LEVEL *level,
}
}
+ tree->node_count++;
if (parent)
parent->nchild++;
diff --git a/crypto/x509v3/pcy_tree.c b/crypto/x509v3/pcy_tree.c
index 6e8322cbc5..6c7fd35405 100644
--- a/crypto/x509v3/pcy_tree.c
+++ b/crypto/x509v3/pcy_tree.c
@@ -13,6 +13,18 @@
#include "pcy_local.h"
+/*
+ * If the maximum number of nodes in the policy tree isn't defined, set it to
+ * a generous default of 1000 nodes.
+ *
+ * Defining this to be zero means unlimited policy tree growth which opens the
+ * door on CVE-2023-0464.
+ */
+
+#ifndef OPENSSL_POLICY_TREE_NODES_MAX
+# define OPENSSL_POLICY_TREE_NODES_MAX 1000
+#endif
+
/*
* Enable this to print out the complete policy tree at various point during
* evaluation.
@@ -168,6 +180,9 @@ static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
return X509_PCY_TREE_INTERNAL;
}
+ /* Limit the growth of the tree to mitigate CVE-2023-0464 */
+ tree->node_maximum = OPENSSL_POLICY_TREE_NODES_MAX;
+
/*
* http://tools.ietf.org/html/rfc5280#section-6.1.2, figure 3.
*
@@ -184,7 +199,7 @@ static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
level = tree->levels;
if ((data = policy_data_new(NULL, OBJ_nid2obj(NID_any_policy), 0)) == NULL)
goto bad_tree;
- if (level_add_node(level, data, NULL, tree) == NULL) {
+ if (level_add_node(level, data, NULL, tree, 1) == NULL) {
policy_data_free(data);
goto bad_tree;
}
@@ -243,7 +258,8 @@ static int tree_init(X509_POLICY_TREE **ptree, STACK_OF(X509) *certs,
* Return value: 1 on success, 0 otherwise
*/
static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
- X509_POLICY_DATA *data)
+ X509_POLICY_DATA *data,
+ X509_POLICY_TREE *tree)
{
X509_POLICY_LEVEL *last = curr - 1;
int i, matched = 0;
@@ -253,13 +269,13 @@ static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
X509_POLICY_NODE *node = sk_X509_POLICY_NODE_value(last->nodes, i);
if (policy_node_match(last, node, data->valid_policy)) {
- if (level_add_node(curr, data, node, NULL) == NULL)
+ if (level_add_node(curr, data, node, tree, 0) == NULL)
return 0;
matched = 1;
}
}
if (!matched && last->anyPolicy) {
- if (level_add_node(curr, data, last->anyPolicy, NULL) == NULL)
+ if (level_add_node(curr, data, last->anyPolicy, tree, 0) == NULL)
return 0;
}
return 1;
@@ -272,7 +288,8 @@ static int tree_link_matching_nodes(X509_POLICY_LEVEL *curr,
* Return value: 1 on success, 0 otherwise.
*/
static int tree_link_nodes(X509_POLICY_LEVEL *curr,
- const X509_POLICY_CACHE *cache)
+ const X509_POLICY_CACHE *cache,
+ X509_POLICY_TREE *tree)
{
int i;
@@ -280,7 +297,7 @@ static int tree_link_nodes(X509_POLICY_LEVEL *curr,
X509_POLICY_DATA *data = sk_X509_POLICY_DATA_value(cache->data, i);
/* Look for matching nodes in previous level */
- if (!tree_link_matching_nodes(curr, data))
+ if (!tree_link_matching_nodes(curr, data, tree))
return 0;
}
return 1;
@@ -311,7 +328,7 @@ static int tree_add_unmatched(X509_POLICY_LEVEL *curr,
/* Curr may not have anyPolicy */
data->qualifier_set = cache->anyPolicy->qualifier_set;
data->flags |= POLICY_DATA_FLAG_SHARED_QUALIFIERS;
- if (level_add_node(curr, data, node, tree) == NULL) {
+ if (level_add_node(curr, data, node, tree, 1) == NULL) {
policy_data_free(data);
return 0;
}
@@ -373,7 +390,7 @@ static int tree_link_any(X509_POLICY_LEVEL *curr,
}
/* Finally add link to anyPolicy */
if (last->anyPolicy &&
- level_add_node(curr, cache->anyPolicy, last->anyPolicy, NULL) == NULL)
+ level_add_node(curr, cache->anyPolicy, last->anyPolicy, tree, 0) == NULL)
return 0;
return 1;
}
@@ -555,7 +572,7 @@ static int tree_calculate_user_set(X509_POLICY_TREE *tree,
extra->qualifier_set = anyPolicy->data->qualifier_set;
extra->flags = POLICY_DATA_FLAG_SHARED_QUALIFIERS
| POLICY_DATA_FLAG_EXTRA_NODE;
- node = level_add_node(NULL, extra, anyPolicy->parent, tree);
+ node = level_add_node(NULL, extra, anyPolicy->parent, tree, 1);
}
if (!tree->user_policies) {
tree->user_policies = sk_X509_POLICY_NODE_new_null();
@@ -582,7 +599,7 @@ static int tree_evaluate(X509_POLICY_TREE *tree)
for (i = 1; i < tree->nlevel; i++, curr++) {
cache = policy_cache_set(curr->cert);
- if (!tree_link_nodes(curr, cache))
+ if (!tree_link_nodes(curr, cache, tree))
return X509_PCY_TREE_INTERNAL;
if (!(curr->flags & X509_V_FLAG_INHIBIT_ANY)

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@ -0,0 +1,48 @@
From b013765abfa80036dc779dd0e50602c57bb3bf95 Mon Sep 17 00:00:00 2001
From: Matt Caswell <matt@openssl.org>
Date: Tue, 7 Mar 2023 16:52:55 +0000
Subject: [PATCH] Ensure that EXFLAG_INVALID_POLICY is checked even in leaf
certs
Even though we check the leaf cert to confirm it is valid, we
later ignored the invalid flag and did not notice that the leaf
cert was bad.
Fixes: CVE-2023-0465
Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20588)
diff --git a/crypto/x509/x509_vfy.c b/crypto/x509/x509_vfy.c
index 925fbb5412..1dfe4f9f31 100644
--- a/crypto/x509/x509_vfy.c
+++ b/crypto/x509/x509_vfy.c
@@ -1649,18 +1649,25 @@ static int check_policy(X509_STORE_CTX *ctx)
}
/* Invalid or inconsistent extensions */
if (ret == X509_PCY_TREE_INVALID) {
- int i;
+ int i, cbcalled = 0;
/* Locate certificates with bad extensions and notify callback. */
- for (i = 1; i < sk_X509_num(ctx->chain); i++) {
+ for (i = 0; i < sk_X509_num(ctx->chain); i++) {
X509 *x = sk_X509_value(ctx->chain, i);
if (!(x->ex_flags & EXFLAG_INVALID_POLICY))
continue;
+ cbcalled = 1;
if (!verify_cb_cert(ctx, x, i,
X509_V_ERR_INVALID_POLICY_EXTENSION))
return 0;
}
+ if (!cbcalled) {
+ /* Should not be able to get here */
+ X509err(X509_F_CHECK_POLICY, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+ /* The callback ignored the error so we return success */
return 1;
}
if (ret == X509_PCY_TREE_FAILURE) {