[smaccona]

Apple is definitely not the worst in this regard, but the most recent version of iOS to support the iPad 3rd generation (the device we are discussing which is being used as a PDF reader) is iOS 9.3.5 (a security/bugfix release on August 25, 2016 which supports the WiFi-only version of the iPad 3rd generation) or iOS 9.3.6 (also a bugfix release on July 22, 2019 which supports the WiFi+cellular version of the same device - specifically, this was a fix to keep GPS working).

The iPad 3rd generation was released in 2012, so the 2016 9.3.5 iOS release gave 4 years of security/bugfix support for the WiFi-only version of that device.

[Schiendelman]

Sure, but there haven't been any security exploits in that version of iOS since then. It still works.

[kennywinker]

Not sure what you’re meaning? A CVE like this: https://nvd.nist.gov/vuln/detail/CVE-2025-24201 found in 2025 impacts iOS versions before 18.3.1 (Safari and iOS are shipped together).

Which means there is a decent chance an iPad running 9.3.2 is vulnerable.

And there have been thousands of CVEs since 9.3.2. Most of low severity, but not all.