When curl >= 7.20.0 and <= 7.78.0 connects to an IMAP or POP3 server to retrieve data using STARTTLS to upgrade to TLS security, the server can respond and send back multiple responses at once that curl caches. curl would then upgrade to TLS but not flush the in-queue of cached responses but instead continue using and trustingthe responses it got *before* the TLS handshake as if they were authenticated.Using this flaw, it allows a Man-In-The-Middle attacker to first inject the fake responses, then pass-through the TLS traffic from the legitimate server and trick curl into sending data back to the user thinking the attacker's injected data comes from the TLS-protected server.

A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server (`--ssl-reqd` on the command line or`CURLOPT_USE_SSL` set to `CURLUSESSL_CONTROL` or `CURLUSESSL_ALL` withlibcurl). This requirement could be bypassed if the server would return a properly crafted but perfectly legitimate response.This flaw would then make curl silently continue its operations **withoutTLS** contrary to the instructions and expectations, exposing possibly sensitive data in clear text over the network.

A permissions issue was addressed with improved validation. This issue is fixed in macOS Big Sur 11.4. A malicious application may be able to bypass Privacy preferences. Apple is aware of a report that this issue may have been actively exploited..

Processing a maliciously crafted image may lead to disclosure of user information. This issue is fixed in macOS Big Sur 11.4, tvOS 14.6, watchOS 7.5, iOS 14.6 and iPadOS 14.6. This issue was addressed with improved checks.

A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.4. A local user may be able to load unsigned kernel extensions.

This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.4. A person with physical access to a Mac may be able to bypass Login Window during a software update.

A memory corruption issue was addressed with improved state management. This issue is fixed in watchOS 7.4.1, iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, macOS Big Sur 11.3.1. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.3, watchOS 7.4. Processing a maliciously crafted image may lead to arbitrary code execution.

A logic issue was addressed with improved state management. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6. A malicious application may be able to bypass certain Privacy preferences.

This issue was addressed with improved checks. This issue is fixed in iOS 14.7, Safari 14.1.2, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7. Processing maliciously crafted web content may lead to code execution.

An out-of-bounds write was addressed with improved input validation. This issue is fixed in iOS 14.7, macOS Big Sur 11.5. Processing a maliciously crafted image may lead to arbitrary code execution.

An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 14.7, macOS Big Sur 11.5. Processing a maliciously crafted file may disclose user information.

An out-of-bounds read was addressed with improved input validation. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7, Security Update 2021-004 Catalina. Processing a maliciously crafted font file may lead to arbitrary code execution.

This issue was addressed with improved checks. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7, Security Update 2021-005 Mojave, Security Update 2021-004 Catalina. Processing a maliciously crafted tiff file may lead to a denial-of-service or potentially disclose memory contents.

A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7, Security Update 2021-004 Catalina. Processing a maliciously crafted image may lead to arbitrary code execution.

Multiple issues were addressed with improved logic. This issue is fixed in macOS Big Sur 11.5. A local attacker may be able to execute code on the Apple T2 Security Chip.

This issue was addressed with improved checks. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7. Processing a maliciously crafted image may lead to arbitrary code execution.

A logic issue was addressed with improved validation. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7, Security Update 2021-004 Catalina. Playing a malicious audio file may lead to an unexpected application termination.

A memory corruption issue was addressed with improved state management. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7, Security Update 2021-004 Catalina. Processing a maliciously crafted audio file may lead to arbitrary code execution.

A logic issue was addressed with improved validation. This issue is fixed in iOS 14.7, macOS Big Sur 11.5, watchOS 7.6, tvOS 14.7. A malicious application may be able to gain root privileges.