A critical vulnerability exposed by security researchers might allow an attacker to decrypt and intercept secured communication exchange between user, websites and mail server’s worldwide. This Logjam affects transport layer security protocol that VPN server, websites and mail server use to encrypt traffic. It may provide attacker sitting between server and user to lower encryption to more easily crack. The researcher found flaw affects minimum 8.4% of web browser.
The susceptibility that follows other serious infrastructure like Freak and Heartbleed, has established from 1990s but it was recently opened. According to researcher, the flaws could be easily used by NSA to crack protected VPN connections. The flaws affects any server which helps DHE_EXPORT ciphers to encode traffic. DHE is abbreviated as Diffie-Hellman algorithm that is utilized by browser and server to share secret key and transfer secure connection for communication. The DHE method is considered to be secure because the key is not static, it can be changed. To spy such traffic, attacker must determine every new key. Though, Logjam flaw will allow attacker to downgrade encryption to a level which could be easily cracked. To secure DHE algorithm, they use 2048 bit prime number to create the keys. But, flaw could downgrade it to force browser and server to use 512 bit primes to create keys. Apparatus used in their own labs were able to crack encryption by utilizing 768 bit primes and believe in intelligence agencies like NSA, with more resource which can easily crack 1024 bit primes. In 1990s, flaw exists to prevent developers from exporting high grade level of crypto and could provide only lower level of protection abroad. Hence, web server must support weak encryption to facilitate communication with those users. Flaw works on any server that supports DHE version that uses 512 bit primes to generate keys. The security hole is hyped severely, but others are warning that its use is limited. The CEO of Errata Security, agrees with researchers that it is good chance to for NSA to crack VPN connections but it is a rumor. But some researchers who revealed the flaw was responsible for exposing Freak vulnerability which was affected by transport layer security protocol. The researchers worked on number of wed site before announcing flaw, so they may remove support of DHE export ciphers.