A micropatch implementing Microsoft's workaround for the actively exploited zero-day remote code execution (RCE) vulnerability impacting Internet Explorer is now available via the 0patch platform until an official fix will be released. Microsoft's advisory says that the company is aware of "limited targeted attacks" targeting the flaw tracked as CVE-2020-0674. The vulnerability, reported by Clément Lecigne of Google’s Threat Analysis Group and Ella Yu from Qihoo 360, "could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user" according to Microsoft. If the user is logged on with administrative permissions on a compromised device, attackers can take full control of the system allowing for program installation and data manipulation, or the possibility to create accounts with full user rights. While no patch for this security issue has been provided so far, Redmond is working on a fix that could be pushed out as an out-of-band security update before next month's Patch Tuesday, just as it happened when a very similar Internet Explorer RCE zero-day was fixed in September 2019. As 0patch found, the mitigation provided by Redmond also comes with several other negative side effects. 0patch created and released a micropatch for Internet Explorer 11, the latest version of the web browser, ready to be applied on fully-patched devices running of Windows 7, Windows 10 v1709/v1803/v1809, Windows Server 2008 R2, and Windows Server 2019. Applying it on these systems will also protect Windows 7 and Windows Server 2008 R2 users that haven't enrolled in the Extended Security Updates program in the event that Microsoft won't be releasing security fixes for their platform. "Our micropatch works like a switch that disables or enables the use of vulnerable jscript.dll by Internet Explorer's browser component in various applications (IE, Outlook, Word,...)," 0patch co-founder Mitja Kolsek explained. "If you're a 0patch user, you already have this micropatch downloaded to all your online computers with 0patch Agent, and - depending on your settings - already automatically applied to all processes using the Internet Explorer 11 engine for rendering content. For more in-depth reading visit OUR FORUM.

Two proofs-of-concept (PoC) exploits have been publicly released for the recently-patched crypto-spoofing vulnerability found by the National Security Agency and reported to Microsoft. The vulnerability (CVE-2020-0601) could enable an attacker to spoof a code-signing certificate (necessary for validating executable programs in Windows) in order to make it appear like an application was from a trusted source. The flaw made headlines when it was disclosed earlier this week as part of Microsoft’s January Patch Tuesday security bulletin. It marked the first time the NSA had ever publicly reported a bug to Microsoft. The two PoC exploits were published to GitHub on Thursday. Either could potentially allow an attacker to launch MitM (man-in-the-middle) attacks – allowing an adversary to spoof signatures for files and emails and fake signed-executable code inside programs that are launched inside Windows. One PoC exploit was released by Kudelski Security and the other by a security researcher under the alias “Ollypwn”. According to Microsoft’s advisory, the spoofing vulnerability exists in the way Windows CryptoAPI (Microsoft’s API that enables developers to secure Windows-based applications using cryptography) validates Elliptic Curve Cryptography (ECC) certificates. Kudelski Security in a blog post said they launched the PoC using a “curve P384” certificate, which uses ECC (specifically, the USERTrust ECC Certificate Authority). Researchers were able to craft a key used to sign the “curve P384” certificate with an arbitrary domain name. This certificate would subsequently be recognized by Windows’ CryptoAPI as trusted. Another similar PoC exploit was publicly released by Denmark-based security expert “Ollypwn.” “When Windows checks whether the certificate is trusted, it’ll see that it has been signed by our spoofed CA,” said “Ollypwn” in a write up of his PoC exploit. “It then looks at the spoofed CA’s public key to check against trusted CA’s. Then it simply verifies the signature of our spoofed CA with the spoofed CA’s generator – this is the issue.” A third PoC exploit was developed by security expert Saleem Rashid; who said on Twitter, Wednesday, that the PoC allowed him to fake TLS certificates and set up sites that look like legitimate ones. However, Rashid did not make his PoC exploit code public. To read the warnings, and more please visit OUR FORUM.