1. Vulnerability description
Fragile SSL encryption algorithm is also called weak encryption algorithm, openssl's FREAK Attack vulnerability. It has been two or three years, and CVE is CVE-2015-0204. If the website or software supports low-strength encryption protocols, including the low version of openssl, this problem will exist. In fact, it is the website of https, the encryption level is relatively low. The hazard is that in the s3_clnt.c file in the OpenSSL library, the ssl3_get_key_exchange function allows the client to use a weak RSA key to launch an RSA-to-EXPORT_RSA downgrade attack on the SSL server, so as to perform brute force cracking and obtain the server secret. key. This problem exists in OpenSSL version before 0.9.8zd, or 1.0.0 before 1.0.0p, or 1.0.1 before 1.0.1k.
Simply put, the website supports low-strength encryption protocols. Hackers can use weak SSL encryption algorithm vulnerabilities to brute force to obtain the server secret key, thereby stealing transmission content.
2. Detection
It can be detected through online detection websites, or directly scanned by tools, such as AWVS, APPscan, etc. (this vulnerability is generally ignored when digging holes).
1. Under windows, you can directly use the SSLciphercheck software to run under CMD to detect, the command is as follows:
sslciphercheck.exe -h ip或域名 -p 4432. The FREAK Attack vulnerability of openssl under linux can be remotely checked by https:
openssl s_client -connect www.fbi.gov:443 -cipher EXPORT If the sentence "alert handshake failure" appears, it means that the website is safe.
3. RedHat series inspection commands:
rpm -qa|grep openssl 4. Debian\Ubuntu series check commands
dpkg -l|grep openssl
In the execution result, if it is white Unsupported, it means it is not supported, if it is red Supported, it means there is a problem, if it is green Supported, it means that it is a supported strong encryption method.