Apple Fixes “chaiOS” Text Bomb Bug Along with Several Other Security Issues with iOS 11.2.5

Apple released iOS 11.2.5 to iPhones, iPads and iPod touch today. The build fixes a number of security issues, including the latest "text bomb" bug that was released by a security researcher who had opted to make it public instead of sharing it with the iPhone maker. Naming it as "chaiOS," the security researcher had said that "Apple needs to take such bugs more seriously."

While it was yet another text-string bug that rendered iPhones frozen, in some cases users were unable to get rid of it completely as Messages app kept crashing. [More details here] The bug has been fixed by Apple by addressing a resource exhaustion issue through improved input validation.

How to Downgrade iOS 11.2.6 to iOS 11.2.5 – And Why You Shouldn’t, Really

iOS 11.2.5 changelog - what's fixed

Apart from chaiOS, iOS 11.2.5 also fixes several other security issues, including several that could lead to arbitrary code execution and give apps access to restricted memory. Here's the complete changelog:

Audio

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: Processing a maliciously crafted audio file may lead to arbitrary code execution

Description: A memory corruption issue was addressed through improved input validation.

CVE-2018-4094: Mingi Cho, MinSik Shin, Seoyoung Kim, Yeongho Lee and Taekyoung Kwon of the Information Security Lab, Yonsei University

Core Bluetooth

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: An application may be able to execute arbitrary code with system privileges

Description: A memory corruption issue was addressed with improved memory handling.

CVE-2018-4087: Rani Idan (@raniXCH) of Zimperium zLabs Team

CVE-2018-4095: Rani Idan (@raniXCH) of Zimperium zLabs Team

Kernel

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: An application may be able to read restricted memory

Description: A memory initialization issue was addressed through improved memory handling.

CVE-2018-4090: Jann Horn of Google Project Zero

Kernel

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: An application may be able to read restricted memory

Description: A race condition was addressed through improved locking.

CVE-2018-4092: an anonymous researcher

Kernel

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: A malicious application may be able to execute arbitrary code with kernel privileges

Description: A memory corruption issue was addressed through improved input validation.

CVE-2018-4082: Russ Cox of Google

Kernel

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: An application may be able to read restricted memory

Description: A validation issue was addressed with improved input sanitization.

CVE-2018-4093: Jann Horn of Google Project Zero

>> LinkPresentation

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: Processing a maliciously crafted text message may lead to application denial of service

Description: A resource exhaustion issue was addressed through improved input validation.

CVE-2018-4100: Abraham Masri (@cheesecakeufo)

QuartzCore

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: Processing maliciously crafted web content may lead to arbitrary code execution

Description: A memory corruption issue existed in the processing of web content. This issue was addressed through improved input validation.

CVE-2018-4085: Ret2 Systems Inc. working with Trend Micro's Zero Day Initiative

Security

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: A certificate may have name constraints applied incorrectly

Description: A certificate evaluation issue existed in the handling of name constraints. This issue was addressed through improved trust evaluation of certificates.

CVE-2018-4086: Ian Haken of Netflix

WebKit

Available for: iPhone 5s and later, iPad Air and later, and iPod touch 6th generation

Impact: Processing maliciously crafted web content may lead to arbitrary code execution

Description: Multiple memory corruption issues were addressed with improved memory handling.

CVE-2018-4088: Jeonghoon Shin of Theori

CVE-2018-4089: Ivan Fratric of Google Project Zero

CVE-2018-4096: found by OSS-Fuzz