diff options
Diffstat (limited to 'debian/patches/CVE-2017-7521bis.patch')
| -rw-r--r-- | debian/patches/CVE-2017-7521bis.patch | 74 |
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; + } |