Both problems could result in large-scale attacks and require massive cleanup.
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The web is a bit of a hot mess today following the discovery of two severe vulnerabilities, according to security releases seen by Ars Technica. The first involves TLS certificates with extremely weak encryption that could affect everything from VPNs to IoT devices. The other is a severe PHP programming language vulnerability impacting CMS systems including WordPress and Drupal. Both problems could result in large-scale attacks and require massive cleanup jobs, security experts said.
gPHP Foundation said on X that it's releasing security patches for two critical vulnerabilities rated 9.2 out of 10 on the severity scale. Ahead of the release today at 14:00 UTC (10AM ET), the group said that "PHP users are encouraged to prepare to update," adding that it will issue an "earlier release if details become public or active exploit evidence."
The advisory follows a report showing video of a tool called PHP2Shell running code on web servers including the latest versions of WordPress, MediaWiki, Symphony, Drupal and other PHP-based sites. The security firm watchTowr claims it has confirmed the vulnerability and that it affects every version from PHP 5 (2004) onward. "According to an unverified report, the vulnerability would let an attacker run their own code on a server running PHP, potentially taking control of it," watchTowr's FAQ on the exploit states.
Another company, Sansec, said it expects "mass attacks to start within 15 minutes of the release." With all this, web admins are likely scrambling to patch the issue, so some PHP-based websites could go down briefly while that happens.
The other issue with TLS certificates is a whole other bag of excrement. An India-based firm called eMudhra said eight of its intermediate CA certificates have been compromised that "chain to roots trusted by Mozilla, Microsoft, Apple and Chrome root programs and by many downstream trust stores." The issue is that the private keys are weak and could let attackers forge credentials for a range of websites and apps.
The compromised private key sizes ranged from three to eight bits, rather than the usual 384 bits. Specifically, the private keys used by eMudhra were 4, 56, 66, 115, 155, 156, 230 and 237, according to Hacker News and other reports. Those would allow anyone to recover them by testing just 256 possible numbers.
The eMudhra certificates were widely trusted by hosts like Cloudflare, as well as browsers, operating systems, IoT (Internet of Things) and other devices that connect to the internet. Once they forge domain certificates, attackers can use those domains to impersonate servers and intercept traffic.
Mozilla, Google and Apple have blocked the compromised certificates for their browsers. However, Mozilla's security expert Dennis Jackson warned that a macOS utility may keep trusting the compromised certificates as it doesn't check for revocation information — something that applies to many other clients as well. eMudhra has revoked the eight certificates and blamed a script used to generate them.
As it stands, the biggest risk is currently to VPNs, particularly where governments actively try to intercept traffic. However, it may also impact IoT devices, unmaintained servers and other parts of the net. "This will be a massive cleanup job, bigger than Heartbleed," cryptography engineer Filippo Valsorda told Ars, referring to a previous TLS bug that caused mass attacks back in 2014.