A text string in the Sindhi language can crash iPhone, iPad, Mac, or Watch when devices receive a notification with it; bug seems to be fixed in iOS 13.4.5 beta
Every so often, a bug in iOS emerges where a certain string of text will cause your iPhone or iPad to crash.
Context & Ripple Effects
This is at least the third time in five years that a single text string has taken down Apple devices. The 2015 Messages crash rebooted iPhones on receipt of one specific string, then spread to Snapchat chats and Twitter DMs within days. In 2018 an Indian character blocked access to Messages, Messenger and WhatsApp across iOS and macOS until it was patched in the iOS 11.3 beta.
The new variant is broader in reach: a Sindhi-language string delivered via any notification can crash iPhone, iPad, Mac and Watch at once, meaning victims need not open an app to be hit. As before, the working fix lives first in a beta — iOS 13.4.5 — leaving the installed base exposed until it ships.
First-order effects
- Any user whose device receives a notification containing the Sindhi string loses the device to repeated crashes; there is no app-level avoidance because notifications bypass user action.
- Apple's only remedy is the iOS 13.4.5 beta, so users on stable releases must wait for the public update while the string circulates.
Second-order effects
- Third-party apps become involuntary vectors again, as they were in 2015 when Snapchat and Twitter carried the earlier string — any service delivering push notifications inherits the crash without shipping its own code.
- Each recurrence forces Apple into the same response pattern seen with the 2018 character bug: acknowledge, seed the fix in a beta, and ship broadly — a cycle measured in weeks during which the payload remains effective.
Third-order effects
- If the pattern holds — 2015, 2018, 2020 — shared Unicode text-rendering code across iPhone, iPad, Mac and Watch will keep turning one parser flaw into a four-platform outage, making Apple's unified OS stack both the vulnerability and the reason a single patch fixes all of it.
- Notification delivery as an attack surface may push platform vendors toward sanitizing incoming text before render time rather than relying on post-incident patches.
The trend: Text-string crash bugs recur on Apple platforms every few years because one shared text-rendering stack spans iPhone, iPad, Mac and Watch, so each Unicode edge case found becomes a cross-device outage fixed only by the next OS release.