From d3b6dfd70db844c4499bec6ad6601623a565e674 Mon Sep 17 00:00:00 2001

From: Tomas Mraz <tomas@openssl.org>

Date: Wed, 18 Jan 2023 09:27:53 +0100

Subject: [PATCH 15/18] pk7_doit.c: Check return of BIO_set_md() calls

These calls invoke EVP_DigestInit() which can fail for digests

with implicit fetches. Subsequent EVP_DigestUpdate() from BIO_write()

or EVP_DigestFinal() from BIO_read() will segfault on NULL

dereference. This can be triggered by an attacker providing

PKCS7 data digested with MD4 for example if the legacy provider

is not loaded.

If BIO_set_md() fails the md BIO cannot be used.

CVE-2023-0401

Reviewed-by: Paul Dale <pauli@openssl.org>

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>

---

 crypto/pkcs7/pk7_doit.c | 12 ++++++++++--

 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/crypto/pkcs7/pk7_doit.c b/crypto/pkcs7/pk7_doit.c

index bde9ac4787..5e562fbea5 100644

--- a/crypto/pkcs7/pk7_doit.c

+++ b/crypto/pkcs7/pk7_doit.c

@@ -84,7 +84,11 @@ static int pkcs7_bio_add_digest(BIO **pbio, X509_ALGOR *alg,

     }

     (void)ERR_pop_to_mark();

-    BIO_set_md(btmp, md);

+    if (BIO_set_md(btmp, md) <= 0) {

+        ERR_raise(ERR_LIB_PKCS7, ERR_R_BIO_LIB);

+        EVP_MD_free(fetched);

+        goto err;

+    }

     EVP_MD_free(fetched);

     if (*pbio == NULL)

         *pbio = btmp;

@@ -522,7 +526,11 @@ BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)

             }

             (void)ERR_pop_to_mark();

-            BIO_set_md(btmp, md);

+            if (BIO_set_md(btmp, md) <= 0) {

+                EVP_MD_free(evp_md);

+                ERR_raise(ERR_LIB_PKCS7, ERR_R_BIO_LIB);

+                goto err;

+            }

             EVP_MD_free(evp_md);

             if (out == NULL)

                 out = btmp;

-- 

2.39.1

From a0f2359613f50b5ca6b74b78bf4b54d7dc925fd2 Mon Sep 17 00:00:00 2001

From: Tomas Mraz <tomas@openssl.org>

Date: Wed, 18 Jan 2023 17:07:24 +0100

Subject: [PATCH 16/18] Add testcase for missing return check of BIO_set_md()

 calls

Reviewed-by: Paul Dale <pauli@openssl.org>

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>

---

 test/recipes/80-test_cms.t                  | 15 ++++++++--

 test/recipes/80-test_cms_data/pkcs7-md4.pem | 32 +++++++++++++++++++++

 2 files changed, 45 insertions(+), 2 deletions(-)

 create mode 100644 test/recipes/80-test_cms_data/pkcs7-md4.pem

diff --git a/test/recipes/80-test_cms.t b/test/recipes/80-test_cms.t

index fd53683e6b..d45789de70 100644

--- a/test/recipes/80-test_cms.t

+++ b/test/recipes/80-test_cms.t

@@ -13,7 +13,7 @@ use warnings;

 use POSIX;

 use File::Spec::Functions qw/catfile/;

 use File::Compare qw/compare_text compare/;

-use OpenSSL::Test qw/:DEFAULT srctop_dir srctop_file bldtop_dir bldtop_file with/;

+use OpenSSL::Test qw/:DEFAULT srctop_dir srctop_file bldtop_dir bldtop_file with data_file/;

 use OpenSSL::Test::Utils;

@@ -50,7 +50,7 @@ my ($no_des, $no_dh, $no_dsa, $no_ec, $no_ec2m, $no_rc2, $no_zlib)

 $no_rc2 = 1 if disabled("legacy");

-plan tests => 13;

+plan tests => 14;

 ok(run(test(["pkcs7_test"])), "test pkcs7");

@@ -941,6 +941,17 @@ subtest "CMS binary input tests\n" => sub {

        "verify binary input with -binary missing -crlfeol");

 };

+# Test case for missing MD algorithm (must not segfault)

+

+with({ exit_checker => sub { return shift == 4; } },

+    sub {

+        ok(run(app(['openssl', 'smime', '-verify', '-noverify',

+                    '-inform', 'PEM',

+                    '-in', data_file("pkcs7-md4.pem"),

+                   ])),

+            "Check failure of EVP_DigestInit is handled correctly");

+    });

+

 sub check_availability {

     my $tnam = shift;

diff --git a/test/recipes/80-test_cms_data/pkcs7-md4.pem b/test/recipes/80-test_cms_data/pkcs7-md4.pem

new file mode 100644

index 0000000000..ecff611deb

--- /dev/null

+++ b/test/recipes/80-test_cms_data/pkcs7-md4.pem

@@ -0,0 +1,32 @@

+-----BEGIN PKCS7-----

+MIIFhAYJKoZIhvcNAQcCoIIFdTCCBXECAQExDjAMBggqhkiG9w0CBAUAMB0GCSqG

+SIb3DQEHAaAQBA5UZXN0IGNvbnRlbnQNCqCCAyQwggMgMIICCKADAgECAgECMA0G

+CSqGSIb3DQEBCwUAMA0xCzAJBgNVBAMMAkNBMCAXDTE2MDExNTA4MTk0OVoYDzIx

+MTYwMTE2MDgxOTQ5WjAZMRcwFQYDVQQDDA5zZXJ2ZXIuZXhhbXBsZTCCASIwDQYJ

+KoZIhvcNAQEBBQADggEPADCCAQoCggEBAKj/iVhhha7e2ywP1XP74reoG3p1YCvU

+fTxzdrWu3pMvfySQbckc9Io4zZ+igBZWy7Qsu5PlFx//DcZD/jE0+CjYdemju4iC

+76Ny4lNiBUVN4DGX76qdENJYDZ4GnjK7GwhWXWUPP2aOwjagEf/AWTX9SRzdHEIz

+BniuBDgj5ed1Z9OUrVqpQB+sWRD1DMFkrUrExjVTs5ZqghsVi9GZq+Seb5Sq0pbl

+V/uMkWSKPCQWxtIZvoJgEztisO0+HbPK+WvfMbl6nktHaKcpxz9K4iIntO+QY9fv

+0HJJPlutuRvUK2+GaN3VcxK4Q8ncQQ+io0ZPi2eIhA9h/nk0H0qJH7cCAwEAAaN9

+MHswHQYDVR0OBBYEFOeb4iqtimw6y3ZR5Y4HmCKX4XOiMB8GA1UdIwQYMBaAFLQR

+M/HX4l73U54gIhBPhga/H8leMAkGA1UdEwQCMAAwEwYDVR0lBAwwCgYIKwYBBQUH

+AwEwGQYDVR0RBBIwEIIOc2VydmVyLmV4YW1wbGUwDQYJKoZIhvcNAQELBQADggEB

+AEG0PE9hQuXlvtUULv9TQ2BXy9MmTjOk+dQwxDhAXYBYMUB6TygsqvPXwpDwz8MS

+EPGCRqh5cQwtPoElQRU1i4URgcQMZquXScwNFcvE6AATF/PdN/+mOwtqFrlpYfs3

+IJIpYL6ViQg4n8pv+b/pCwMmhewQLwCGs9+omHNTOwKjEiVoNaprAfj5Lxt15fS2

++zZW0mT9Y4kfEypetrqSAjh8CDK+vaQhkeKdDfJyBfjS4ALfxvCkT3mQnsWFJ9CU

+TVG3uw6ylSPT3wN3RE0Ofa4rI5PESogQsd/DgBc7dcDO3yoPKGjycR3/GJDqqCxC

+e9dr6FJEnDjaDf9zNWyTFHExggITMIICDwIBATASMA0xCzAJBgNVBAMMAkNBAgEC

+MAwGCCqGSIb3DQIEBQCggdQwGAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkq

+hkiG9w0BCQUxDxcNMjMwMTE4MTU0NzExWjAfBgkqhkiG9w0BCQQxEgQQRXO4TKpp

+RgA4XHb8bD1pczB5BgkqhkiG9w0BCQ8xbDBqMAsGCWCGSAFlAwQBKjALBglghkgB

+ZQMEARYwCwYJYIZIAWUDBAECMAoGCCqGSIb3DQMHMA4GCCqGSIb3DQMCAgIAgDAN

+BggqhkiG9w0DAgIBQDAHBgUrDgMCBzANBggqhkiG9w0DAgIBKDANBgkqhkiG9w0B

+AQEFAASCAQAe+xlm/TGg/s/7b0xBc3FFnmmUDEe7ljkehIx61OnBV9ZWA+LcBX/7

+kmMSMdaHjRq4w8FmwBMLzn0ttXVqf0QuPbBF/E6X5EqK9lpOdkUQhNiN2v+ZfY6c

+lrH4ADsSD9D+UHw0sxo5KEF+PPuneUfYCJZosFUJosBbuSEXK0C9yfJoDKVE8Syp

+0vdqh73ogLeNgZLAUGSSB66OmHDxwgAj4qPAv6FHFBy1Xs4uFZER5vniYrH9OrAk

+Z6XdvzDoYZC4XcGMDtcOpOM6D4owqy5svHPDw8wIlM4GVhrTw7CQmuBz5uRNnf6a

+ZK3jZIxG1hr/INaNWheHoPIhPblYaVc6

+-----END PKCS7-----

-- 

2.39.1