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-rw-r--r--debian/patches/CVE-2017-7521bis.patch74
1 files changed, 74 insertions, 0 deletions
diff --git a/debian/patches/CVE-2017-7521bis.patch b/debian/patches/CVE-2017-7521bis.patch
new file mode 100644
index 0000000..8f242f8
--- /dev/null
+++ b/debian/patches/CVE-2017-7521bis.patch
@@ -0,0 +1,74 @@
+commit 2341f716198fa90193e040b3fdb16959a47c6c27
+Author: Steffan Karger <steffan.karger@fox-it.com>
+Date: Mon Jun 19 11:28:38 2017 +0200
+
+ Fix remote-triggerable memory leaks (CVE-2017-7521)
+
+ Several of our OpenSSL-specific certificate-parsing code paths did not
+ always clear all allocated memory. Since a client can cause a few bytes
+ of memory to be leaked for each connection attempt, a client can cause a
+ server to run out of memory and thereby kill the server. That makes this
+ a (quite inefficient) DoS attack.
+
+ When using the --x509-alt-username option on openssl builds with an
+ extension (argument prefixed with "ext:", e.g. "ext:subjectAltName"), the
+ code would not free all allocated memory. Fix this by using the proper
+ free function.
+
+ If ASN1_STRING_to_UTF8() returns 0, it didn't fail and *did* allocate
+ memory. So also free the returned buffer if it returns 0.
+
+ These issues were found, analysed and reported to the OpenVPN team by Guido
+ Vranken.
+
+ CVE: 2017-7521
+ Signed-off-by: Steffan Karger <steffan.karger@fox-it.com>
+ Acked-by: Gert Doering <gert@greenie.muc.de>
+ Acked-by: David Sommerseth <davids@openvpn.net>
+ Acked-by: Guido Vranken <guidovranken@gmail.com>
+ Message-Id: <1497864520-12219-4-git-send-email-steffan.karger@fox-it.com>
+ URL: https://www.mail-archive.com/search?l=mid&q=1497864520-12219-4-git-send-email-steffan.karger@fox-it.com
+ Signed-off-by: Gert Doering <gert@greenie.muc.de>
+ (cherry picked from commit 2d032c7fcdfd692c851ea2fa858b4c2d9ea7d52d)
+
+Index: openvpn-2.4.0/src/openvpn/ssl_verify_openssl.c
+===================================================================
+--- openvpn-2.4.0.orig/src/openvpn/ssl_verify_openssl.c
++++ openvpn-2.4.0/src/openvpn/ssl_verify_openssl.c
+@@ -165,7 +165,7 @@ extract_x509_extension(X509 *cert, char
+ break;
+ }
+ }
+- sk_GENERAL_NAME_free(extensions);
++ GENERAL_NAMES_free(extensions);
+ }
+ return retval;
+ }
+@@ -218,8 +218,7 @@ extract_x509_field_ssl(X509_NAME *x509,
+ {
+ return FAILURE;
+ }
+- tmp = ASN1_STRING_to_UTF8(&buf, asn1);
+- if (tmp <= 0)
++ if (ASN1_STRING_to_UTF8(&buf, asn1) < 0)
+ {
+ return FAILURE;
+ }
+@@ -460,7 +459,7 @@ x509_setenv_track(const struct x509_trac
+ ASN1_STRING *val = X509_NAME_ENTRY_get_data(ent);
+ unsigned char *buf;
+ buf = (unsigned char *)1; /* bug in OpenSSL 0.9.6b ASN1_STRING_to_UTF8 requires this workaround */
+- if (ASN1_STRING_to_UTF8(&buf, val) > 0)
++ if (ASN1_STRING_to_UTF8(&buf, val) >= 0)
+ {
+ do_setenv_x509(es, xt->name, (char *)buf, depth);
+ OPENSSL_free(buf);
+@@ -548,7 +547,7 @@ x509_setenv(struct env_set *es, int cert
+ continue;
+ }
+ buf = (unsigned char *)1; /* bug in OpenSSL 0.9.6b ASN1_STRING_to_UTF8 requires this workaround */
+- if (ASN1_STRING_to_UTF8(&buf, val) <= 0)
++ if (ASN1_STRING_to_UTF8(&buf, val) < 0)
+ {
+ continue;
+ }