CompTIAAvailable
CS0-003
CVE-2024-27834 Apple Multiple Products Vulnerability
CVE-2024-27834 is an Apple pointer authentication bypass that CISA added to its KEV catalog on 2026-11-04. Apple fixed it in May 2024, so the job is to find devices still running older releases.
Short answer: CVE-2024-27834 is an improper authentication flaw in Apple iOS, iPadOS, macOS, Safari, tvOS and watchOS that can bypass Pointer Authentication. Apple fixed it in 2024 releases such as iOS 17.5 and macOS Sonoma 14.5, and CISA added it to KEV on 2026-11-04 with a federal due date of 2026-11-18. Update every Apple device below the fixed versions and confirm the result with a version check.
What happened and why it matters now
CISA added CVE-2024-27834 to its Known Exploited Vulnerabilities (KEV) catalog on 2026-11-04. The flaw is an improper authentication issue in Apple's operating systems and Safari. It lets an attacker who already has arbitrary read and write capability bypass Pointer Authentication.
Apple fixed the bug in May 2024. The NVD record was published on 2024-05-14 and describes the fix as "improved checks." The new KEV listing means devices that skipped those updates now deserve a second look.
Affected and fixed versions
Pointer Authentication is a hardware-backed protection that makes it harder to hijack code execution after a memory bug. This flaw weakens it. The fixed releases are listed in the NVD record.
Product | Fixed in |
|---|---|
Safari |
|
iOS and iPadOS (older line) |
|
iOS and iPadOS |
|
macOS Sonoma |
|
tvOS |
|
watchOS |
|
Anything on these lines running an earlier release has not received the fix. Apple's own notes are at 120896, 120898, 120901, 120902, 120903 and 120905.
How serious it is and whether it is exploited
NVD scores it 5.5 MEDIUM with the vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N. In plain terms, the attacker needs local access and low privileges. The impact is on integrity, not confidentiality or availability. The weakness is tagged CWE-287.
The score understates the practical risk. The attacker must already be able to read and write memory arbitrarily. That usually means another bug came first, so this flaw commonly acts as one link in an exploit chain. The medium score describes the single bug, not the chain.
KEV listing is the key signal. CISA tracks that catalog for vulnerabilities with evidence of active exploitation. Known ransomware use is listed as Unknown. Check the NVD page for updates.
What to do now
CISA's required action is to apply vendor mitigations in line with BOD 26-04, "Prioritizing Security Updates Based on Risk," and its "Forensics Triage Requirements." The federal due date is 2026-11-18. If no mitigation exists for a product, CISA says to stop using it. You also need to judge each asset's internet exposure.
Check a Mac
Run these on each Mac. You need 14.5 or later on Sonoma, and Safari 17.5 or later.
sw_vers -productVersion
defaults read /Applications/Safari.app/Contents/Info CFBundleShortVersionString
softwareupdate --list
sudo softwareupdate --install --all --restartCheck a list of Macs over SSH
Put one hostname per line in macs.txt. This prints each version so you can spot stragglers.
for h in $(cat macs.txt); do echo -n "$h "; ssh "$h" sw_vers -productVersion; done | sort -k2 -VCheck iPhones, iPads, Apple TVs and Watches
On an iPhone or iPad, open Settings > General > Software Update. You need at least 17.5, or 16.7.8 for devices stuck on the older line. Apple TVs need tvOS 17.5. Watches need watchOS 10.5.
If you manage devices through MDM, filter your inventory for OS versions below those numbers. Then push the update and set a deadline.
A worked example: a 20-Mac office
Say your SSH loop returns this output.
design-01 14.4.1
design-02 14.5
front-desk 14.6.1You should treat design-01 as exposed, because 14.4.1 is below 14.5. The other two meet the minimum.
Update design-01 first, then rerun the loop to confirm. Keep that output as your record. If a machine looks suspicious, escalate it for forensic review rather than only patching it.
Prioritizing your devices
Use this table when you cannot patch everything at once.
Device type | Priority | Reason |
|---|---|---|
Laptops that browse the web and travel | Highest | Most exposure to the other bugs that start a chain |
Shared or admin-used Macs | High | Higher-value accounts |
Phones and tablets on | High | Easy to forget in inventories |
Apple TVs and watches | Normal | Still patch them, but exposure is usually lower |
For more on handling actively exploited bugs in other products, see our write-up on Ivanti Connect Secure zero-days chained together.
What IT and security learners can take from it
This CVE shows that a "medium" score can still matter when it sits inside an exploit chain. It also shows that asset inventory and version checks are daily security work, not exam theory. Learners can practice by reading the KEV entry, mapping the CVSS vector, and writing a patch verification plan like the one above. The CompTIA CySA+ CS0-003 voucher ($224.99) covers vulnerability management and prioritization, and you can browse more options in our cybersecurity certifications.
Sources
Questions about this topic
Is CVE-2024-27834 remotely exploitable by itself?
No. The NVD vector shows local access (`AV:L`) and low privileges. The attacker also needs arbitrary read and write capability first, so another flaw is usually involved.
Why is a 2024 bug in CISA's list in November 2026?
CISA added it to KEV on 2026-11-04. The entry lists a federal due date of 2026-11-18. Apple's fixes shipped in May 2024, so the practical question is which devices never received them.
Which minimum versions close the hole?
Safari `17.5`, iOS and iPadOS `17.5` (or `16.7.8` on the older line), macOS Sonoma `14.5`, tvOS `17.5` and watchOS `10.5`. These come from the NVD record.
Does a medium CVSS score mean I can wait?
Not for a KEV-listed bug. The 5.5 score covers this flaw alone. Attackers commonly combine such bugs with others, and CISA's listing signals real-world exploitation.
What should I keep as proof of remediation?
Save the before and after version output for each device, the date you applied the update, and any MDM compliance report. This helps with audits and with the BOD 26-04 asset review CISA asks for.
