SSL-related vulnerability resolution after Tomcat turns on HTTPS

Source: Internet
Author: User
Tags ssl connection asymmetric encryption cve

Recently with the Green League scanning system for the entire network system scanning, several devices were swept out of the SSL-related vulnerabilities, here to make a short note.

This involves a vulnerability

1. Vulnerability Name: SSL 3.0 poodle Attack Information Disclosure Vulnerability (cve-2014-3566) "Principle Scan"

2.ssl/tls Commandment (Bar-mitzvah) attack Vulnerability (cve-2015-2808) "Principle Scan"


Key points of knowledge popularization 1:ssl agreement

SSL (secure Sockets layer Secure sockets) is a secure communication protocol based on Web applications that was first proposed by Netscape (Netscape). SSL between the TCP protocol and the application layer protocol, the main role is to encrypt the HTTP, FTP and other application layer of data encryption and rely on the reliable TCP protocol on the Internet to the destination, the most typical application is HTTPS.

SSL provides 3 basic security services:

1) Identity legitimacy: The data sender and receiver to confirm each other's identity, to ensure that their identities will not be impersonating.

2) Data confidentiality: All transmitted data is encrypted, and to ensure that even if the data is intercepted can not be cracked.

3) Data integrity: Ensure that the data received is consistent with the data sent by the sender and has not been tampered with.

SSL protocol mainly uses the data encryption algorithm:

1) Asymmetric encryption algorithm: Data encryption and decryption using different keys, such as RSA public key encryption algorithm. The advantage is high security level, it is difficult to crack, the disadvantage is that encryption decryption is slow, so only for the small amount of data encryption. The SSL protocol uses the asymmetric encryption algorithm to realize the digital signature, verifies the identity of the data sender (or receiver), and also uses the asymmetric encryption algorithm to exchange the key (the key of the symmetric encryption algorithm for data encryption and the MAC algorithm for data integrity verification).

2) symmetric encryption algorithm: Data encryption and decryption using the same key, such as DES, 3DES, RC4, etc. are symmetric encryption algorithm. The advantage is that the decryption speed is fast and is suitable for the encryption of big data, but the security is poor. The SSL protocol encrypts the transmitted data using the symmetric encryption algorithm.

3) MAC algorithm: Message authentication Codes, that is, messages authentication code algorithm, MAC contains key hash function algorithm, compatible with the characteristics of MD and SHA algorithm, and on this basis added a key. The SSL protocol uses the MAC algorithm to verify the integrity of the message.


Knowledge popularization 2:ssl version of the Protocol

There are currently 5 versions of the SSL protocol in use, namely SSL2.0, SSL3.0, TLS1.0, TLS1.1, and TLS1.2, where the TLS (Transport layer Security, Transport Layer Secure) protocol is an upgraded version of the SSL protocol.

After the SSL protocol exposes the poodle vulnerability, the public platform will cancel the support of the SSLV2, SSLv3 two versions, the browser and other platforms that use SSL protocol will gradually cancel the support for SSLv2, SSLv3, and currently only recommend the use of TLSv1.0, Three versions of TLSv1.1 and TLSv1.2.



1. Vulnerability Name: SSL 3.0 poodle Attack Information Disclosure Vulnerability (cve-2014-3566) "Principle Scan"

Device Vulnerability Service involved

The device affected by this vulnerability mainly because the above system deployed Tomcat HTTPS services, and the Tomcat HTTPS service by default support SSL 3.0 protocol (currently used in the SSL protocol mainly has 5 versions, namely SSL2.0, SSL3.0, TLS1.0 , TLS1.1, and tls1.2.ssl3.0 are outdated and insecure protocols that are currently replaced by TLS 1.0,tls 1.1,TLS 1.2)

Vulnerability description and Utilization

ssl3.0 is an outdated and insecure protocol Was previously replaced by TLS 1.0,tls 1.1,TLS 1.2, because of compatibility reasons, most of the TLS implementations are still compatible with SSL3.0.

for the sake of generality, most of the current browser versions support the SSL3.0,TLS protocol handshake phase that includes the version negotiation steps, in general, the latest protocol version of the client and server side will be used. When it is negotiated with the server-side handshake phase, it first provides the latest version of the protocol it supports, and attempts to negotiate with an older protocol version if the handshake fails. An attacker who was able to implement a man-in-the-middle attack could successfully implement a downgrade attack by enabling the affected version browser to fail a negotiated connection with the server side using the newer protocol, allowing the client to communicate with the server side using an insecure SSL3.0, at which point the SSL 3.0 A vulnerability exists in the implementation of CBC block encryption used by an attacker to successfully decrypt encrypted information for an SSL connection, such as obtaining user cookie data. This attack is known as a poodle attack (Padding Oracle on downgraded Legacy encryption). This vulnerability affects the vast majority of SSL servers and clients with a wide range of effects. However, to be successful, an attacker would need to be able to control the data between the client and the server (performing a man-in-the-middle attack).

Vulnerability Handling Methods

Modify the Tomcat server.xml below to add sslenabledprotocols= "tlsv1,tlsv1.1,tlsv1.2" To turn off SSL V3

<connector port= "8443" protocol= "Org.apache.coyote.http11.Http11NioProtocol" sslenabled= "true"

maxthreads= "Scheme=" "https" secure= "true"

clientauth= "false" sslprotocol= "TLS " sslenabledprotocols= "tlsv1,tlsv1.1,tlsv1.2" ciphers= "Tls_ecdhe_rsa_with_aes_128_cbc_sha256,tls_ecdhe_rsa_with_aes_128_cbc_sha,tls_ecdhe_rsa_with_aes_ 256_cbc_sha384,tls_ecdhe_rsa_with_aes_256_cbc_sha,tls_ecdhe_rsa_with_rc4_128_sha,tls_rsa_with_aes_128_cbc_ Sha256,tls_rsa_with_aes_128_cbc_sha,tls_rsa_with_aes_256_cbc_sha256,tls_rsa_with_aes_256_cbc_sha,ssl_rsa_with_ Rc4_128_sha "

Keystorefile= "/home/kl/.keystore" keystorepass= "eastcom"/>

2.ssl/tls Commandment (Bar-mitzvah) attack Vulnerability (cve-2015-2808) "Principle Scan"

Device Vulnerability Service involved

The device affected by this vulnerability is mainly due to the deployment of the above system Tomcat HTTPS service, the Web container opens the SSL/TLS access mode, does not block RC4 this existence has been effectively cracked encryption algorithm caused.

Vulnerability description and Utilization

The SSL/TLS protocol is a widely used cryptographic protocol, the Bar mitzvah attack actually exploits the "invariant vulnerability", which is a flaw in the RC4 algorithm, which in some cases leaks the ciphertext in SSL/TLS encrypted traffic, and thus the account user name password, Credit card data and other sensitive information leaked to hackers.

Vulnerability Handling Methods

Modify the Tomcat Server.xml to include the red string value below

<connector port= "8443" protocol= "Org.apache.coyote.http11.Http11NioProtocol" sslenabled= "true"

maxthreads= "Scheme=" "https" secure= "true"

Clientauth= "false" sslprotocol= "TLS" sslenabledprotocols= "tlsv1,tlsv1.1,tlsv1.2"

ciphers= "Tls_ecdhe_rsa_witaes_128_cbc_sha256,tls_ecdhe_rsa_with_aes_128_cbc_sha,tls_ecdhe_rsa_ with_aes_256_cbc_sha384,tls_ecdhe_rsa_with_aes_256_cbc_sha,tls_ecdhe_rsa_with_rc4_128_sha,tls_rsa_with_aes_128 _cbc_sha256,tls_rsa_with_aes_128_cbc_sha,tls_rsa_with_aes_256_cbc_sha256,tls_rsa_with_aes_256_cbc_sha,ssl_rsa_ With_rc4_128_sha " keystorefile="/home/kl/.keystore "keystorepass=" new1234 "/>

Local detection of this vulnerability is handled by

If you can see the certificate information, then there is a risk vulnerability

If SSLv3 alerthandshake failure is displayed, the server does not have this vulnerability

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Cite some of the article links:

http://www.secpulse.com/archives/5682.html

http://www.freebuf.com/articles/network/62442.html

http://blog.csdn.net/lyq8479/article/details/40709175

This article is from the "mirror is not Taiwan" blog, please be sure to keep this source http://kk876435928.blog.51cto.com/3530246/1773114

SSL-related vulnerability resolution after Tomcat turns on HTTPS

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