Apple this week released security updates to address multiple vulnerabilities in macOS and Safari, including a flaw that can be exploited for the recently disclosed NAT Slipstreaming 2.0 attack.
As part of the attack, an adversary could set up a crafted website and lure the intended victim into visiting it. As soon as that happens, malicious code on the site starts sending multiple fetch requests from the victim’s browser, allowing the attacker to identify and access devices on the local network.
Devised by Ben Seri and Gregory Vishnipolsky of IoT security company Armis, together with researcher Samy Kamkar, the attack is a variant of the NAT Slipstreaming attack that was detailed in October 2020, and which could be leveraged to target local network services.
Both attacks bypass Network Address Translation (NAT) and firewalls by abusing the browser and the Application Level Gateway (ALG), a connection tracking mechanism in firewalls, NATs, and routers.
Apple, which describes the vulnerability as a port redirection issue in WebRTC, where malicious sites could access restricted ports on arbitrary servers, says additional port validation should resolve the bug in macOS Big Sur 11.2. The bug is tracked as CVE-2021-1799.
A total of 66 vulnerabilities were addressed with the release of macOS Big Sur 11.2, Security Update 2021-001 for Catalina, and Security Update 2021-001 for Mojave, many of them leading to arbitrary code execution, denial of service, privilege escalation, and memory leakage.
The most important of these vulnerabilities are CVE-2021-1870, CVE-2021-1871 (both impact WebKit), and CVE-2021-1782 (affecting Kernel), which have been targeted in attacks.
The bugs, which Apple says were anonymously reported, were found in the iOS and iPadOS mobile platforms, and were addressed last week with a set of emergency patches. The Cupertino-based company has yet to provide specific details on the bugs themselves and on the attacks abusing them.
Both Kernel and WebKit received fixes for other vulnerabilities as well, with the ImageIO component of macOS also seeing patches for a large number of vulnerabilities this week, namely 18.
Triggered during the processing of maliciously crafted images, these vulnerabilities could lead to arbitrary code execution or denial of service. One of them, CVE-2021-1818, could be exploited by a remote attacker for code execution or to cause unexpected application termination.
The Model I/O component received fixes for seven vulnerabilities that could be triggered during the processing of maliciously crafted USD files or images, leading to arbitrary code execution, unexpected application termination, or heap corruption.
Apple patched three vulnerabilities with the release of Safari 14.0.3 this week, namely NAT Slipstreaming 2.0, and two issues in WebKit (CVE-2021-1788 and CVE-2021-1789) that could lead to arbitrary code execution.