OS X El Capitan, Apple's next-generation Mac operating system, has already been rolled out. However, researchers say it is still exposed to serious security flaws in its Gatekeeper and Keychain features.

Patrick Wardle, head of research at Synack, warned that Mac users may be vulnerable to malware infection and password theft via the two security features designed to prevent attacks.

Wardle, during his presentation at the Virus Bulletin conference in Prague on Thursday, Oct. 1, detailed unpatched security flaws he has uncovered which allow hackers to spread unsigned binaries containing malware and bypassing the security tool Gatekeeper.

He explained that the security tool only does one check on app bundle downloads. He added that the tool does not perform further checks when the download is launched.

“Gatekeeper has one job: to block unauthenticated code coming from the Internet," said Wardle. "We’ve completely bypassed this. To me, Gatekeeper is no obstacle at all."

He said the security flaw allowed him to carry out a malicious download containing a legit Apple-signed app and a hidden unsigned malicious file.

Wardle said that when the download was launched, the app also ran the unsigned and totally untrusted malware without the security app noticing the malicious file.

The researcher pointed out that Apple should incorporate additional checks to block the hidden files and warn users about the vulnerability.

Keychain Attack

Meanwhile, the OS X Keychain security flaw was discovered by a group of researchers and has been around since October 2014. The vulnerability involves "poisoning" the password management system with the use of an unauthorized application. This weakness may allow a hacker to delete or even steal users' sensitive data.

XGuardian, an open source tool, however, can help users safeguard their sensitive data from a Keychain attack, according to Luyi Xing of Indiana University Bloomington.

“So if Apple users want to protect themselves before a fix from Apple is finally in place, this app could help," told the researcher.

In September, we reported that OS X 10.11 El Capitan comes with a multitude of new features including performance improvements, refreshed Mission Control and Slip View.