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authorMatt Caswell <matt@openssl.org>2021-02-10 17:10:36 +0100
committerMatt Caswell <matt@openssl.org>2021-02-16 12:32:32 +0100
commit8130d654d1de922ea224fa18ee3bc7262edc39c0 (patch)
treea79a52b871f5a20abe3dcb18fc00805f4a5aa712
parentDo not match RFC 5114 groups without q as it is significant (diff)
downloadopenssl-8130d654d1de922ea224fa18ee3bc7262edc39c0.tar.xz
openssl-8130d654d1de922ea224fa18ee3bc7262edc39c0.zip
Fix Null pointer deref in X509_issuer_and_serial_hash()
The OpenSSL public API function X509_issuer_and_serial_hash() attempts to create a unique hash value based on the issuer and serial number data contained within an X509 certificate. However it fails to correctly handle any errors that may occur while parsing the issuer field (which might occur if the issuer field is maliciously constructed). This may subsequently result in a NULL pointer deref and a crash leading to a potential denial of service attack. The function X509_issuer_and_serial_hash() is never directly called by OpenSSL itself so applications are only vulnerable if they use this function directly and they use it on certificates that may have been obtained from untrusted sources. CVE-2021-23841 Reviewed-by: Richard Levitte <levitte@openssl.org> Reviewed-by: Paul Dale <pauli@openssl.org>
-rw-r--r--crypto/x509/x509_cmp.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/crypto/x509/x509_cmp.c b/crypto/x509/x509_cmp.c
index 8e525a3815..a74311e92d 100644
--- a/crypto/x509/x509_cmp.c
+++ b/crypto/x509/x509_cmp.c
@@ -44,6 +44,8 @@ unsigned long X509_issuer_and_serial_hash(X509 *a)
if (ctx == NULL)
goto err;
f = X509_NAME_oneline(a->cert_info.issuer, NULL, 0);
+ if (f == NULL)
+ goto err;
if (!EVP_DigestInit_ex(ctx, EVP_md5(), NULL))
goto err;
if (!EVP_DigestUpdate(ctx, (unsigned char *)f, strlen(f)))