CVE-2021-30737
published 2021-09-08CVE-2021-30737: A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code. This issue is fixed in tvOS 14.6, Security Update 2021-004…
PriorityP180high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
ITWVulnCheck KEV
Exploited in the wild
EPSS
1.50%
71.4th percentile
A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code. This issue is fixed in tvOS 14.6, Security Update 2021-004 Mojave, iOS 14.6 and iPadOS 14.6, iOS 12.5.4, Security Update 2021-003 Catalina, macOS Big Sur 11.4, watchOS 7.5. Processing a maliciously crafted certificate may lead to arbitrary code execution.
Affected
23 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| apple | ios | — | — |
| apple | ios_and_ipados | >= unspecified < 14.6 | 14.6 |
| apple | ipados | < 14.6 | 14.6 |
| apple | iphone_os | < 12.5.4 | 12.5.4 |
| apple | iphone_os | >= 13.0 < 14.6 | 14.6 |
| apple | mac_os_x | — | — |
| apple | mac_os_x | — | — |
| apple | mac_os_x | — | — |
| apple | mac_os_x | 10.14.0 – 10.14.5 | — |
| apple | mac_os_x | 10.15 – 10.15.5 | — |
| apple | macos | >= 11.0.1 < 11.4 | 11.4 |
| apple | macos | >= unspecified < 11.4 | 11.4 |
| apple | macos | >= unspecified < 2021 | 2021 |
| apple | macos | >= unspecified < 14.6 | 14.6 |
| apple | macos | >= unspecified < 7.5 | 7.5 |
| apple | macos | >= unspecified < 12.5 | 12.5 |
| apple | macos_big_sur | — | — |
| apple | security_update_2021-003_catalina | — | — |
| apple | security_update_2021-004_mojave | — | — |
| apple | tvos | < 14.6 | 14.6 |
| apple | tvos | — | — |
| apple | watchos | < 7.5 | 7.5 |
| apple | watchos | — | — |
Detection & IOCsextracted from sources · hover to see the quote
- →Trigger vector is a maliciously crafted certificate processed by the ASN.1 decoder; monitor for anomalous or oversized certificate parsing activity in Apple Security component ↗
- →Vulnerability resides specifically in the ASN.1 decoder within the Security component across Apple platforms; focus inspection on certificate-handling code paths (e.g., SecCertificate parsing, TLS handshake certificate chains) ↗
- ·Affected platforms span multiple Apple OSes; patched versions are tvOS 14.6, iOS 14.6, iPadOS 14.6, iOS 12.5.4, macOS Big Sur 11.4, Security Update 2021-004 Mojave, Security Update 2021-003 Catalina, and watchOS 7.5 — detection/blocking rules should account for all unpatched versions below these thresholds ↗
- ·The fix was implemented by removing the vulnerable code entirely rather than patching it, meaning no partial mitigations exist in prior versions; any unpatched device processing untrusted certificates is fully exposed ↗
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv2.06.8MEDIUMAV:N/AC:M/Au:N/C:P/I:P/A:P
vulncheck8.8HIGH
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Apple
CVE-2021-30737: iOS 12.5.4
vendor_apple·2021-06-14·CVSS 8.8
CVE-2021-30737 [HIGH] CVE-2021-30737: iOS 12.5.4
Apple Security Update: About the security content of iOS 12.5.4
Product: iOS
Version: 12.5.4
CVE: CVE-2021-30737
Component: Security
Impact: Processing a maliciously crafted certificate may lead to arbitrary code execution
Description: A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code.
Apple
CVE-2021-30737: Security Update 2021-004 Mojave
vendor_apple·2021-05-24·CVSS 8.8
CVE-2021-30737 [HIGH] CVE-2021-30737: Security Update 2021-004 Mojave
Apple Security Update: About the security content of Security Update 2021-004 Mojave
Product: Security Update 2021-004 Mojave
CVE: CVE-2021-30737
Component: Security
Impact: A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code
Description: Processing a maliciously crafted certificate may lead to arbitrary code execution.
Apple
CVE-2021-30737: watchOS 7.5
vendor_apple·2021-05-24·CVSS 8.8
CVE-2021-30737 [HIGH] CVE-2021-30737: watchOS 7.5
Apple Security Update: About the security content of watchOS 7.5
Product: watchOS
Version: 7.5
CVE: CVE-2021-30737
Component: Security
Impact: Processing a maliciously crafted certificate may lead to arbitrary code execution
Description: A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code.
Apple
CVE-2021-30737: macOS Big Sur 11.4
vendor_apple·2021-05-24·CVSS 8.8
CVE-2021-30737 [HIGH] CVE-2021-30737: macOS Big Sur 11.4
Apple Security Update: About the security content of macOS Big Sur 11.4
Product: macOS Big Sur
Version: 11.4
CVE: CVE-2021-30737
Component: Security
Impact: Processing a maliciously crafted certificate may lead to arbitrary code execution
Description: A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code.
Apple
CVE-2021-30737: Security Update 2021-003 Catalina
vendor_apple·2021-05-24·CVSS 8.8
CVE-2021-30737 [HIGH] CVE-2021-30737: Security Update 2021-003 Catalina
Apple Security Update: About the security content of Security Update 2021-003 Catalina
Product: Security Update 2021-003 Catalina
CVE: CVE-2021-30737
Component: Security
Impact: A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code
Description: Processing a maliciously crafted certificate may lead to arbitrary code execution.
Apple
CVE-2021-30737: tvOS 14.6
vendor_apple·2021-05-24·CVSS 8.8
CVE-2021-30737 [HIGH] CVE-2021-30737: tvOS 14.6
Apple Security Update: About the security content of tvOS 14.6
Product: tvOS
Version: 14.6
CVE: CVE-2021-30737
Component: Security
Impact: Processing a maliciously crafted certificate may lead to arbitrary code execution
Description: A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code.
GHSA
GHSA-f7gv-428c-w364: A memory corruption issue in the ASN
ghsa_unreviewed·2022-05-24
CVE-2021-30737 [HIGH] CWE-787 GHSA-f7gv-428c-w364: A memory corruption issue in the ASN
A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code. This issue is fixed in tvOS 14.6, Security Update 2021-004 Mojave, iOS 14.6 and iPadOS 14.6, iOS 12.5.4, Security Update 2021-003 Catalina, macOS Big Sur 11.4, watchOS 7.5. Processing a maliciously crafted certificate may lead to arbitrary code execution.
Project0
CVE-2021-30737, @xerub's 2021 iOS ASN.1 Vulnerability - Project Zero
project_zero·2022-04-01·CVSS 8.8
CVE-2021-30737 [HIGH] CVE-2021-30737, @xerub's 2021 iOS ASN.1 Vulnerability - Project Zero
Posted by Ian Beer, Google Project Zero
This blog post is my analysis of a vulnerability found by @xerub. Phrack published @xerub's writeup so go check that out first.
As well as doing my own vulnerability research I also spend time trying as best as I can to keep up with the public state-of-the-art, especially when details of a particularly interesting vulnerability are announced or a new in-the-wild exploit is caught. Originally this post was just a series of notes I took last year as I was trying to understand this bug. But the bug itself and the narrative around it are so fascinating that I thought it would be worth writing up these notes into a more coherent form to share with the community.
## Background
On April 14th 2021 the Washington Post published an article on the
VulnCheck
Apple ipados Out-of-bounds Write
vulncheck·2021·CVSS 8.8
CVE-2021-30737 [HIGH] Apple ipados Out-of-bounds Write
Apple ipados Out-of-bounds Write
A memory corruption issue in the ASN.1 decoder was addressed by removing the vulnerable code. This issue is fixed in tvOS 14.6, Security Update 2021-004 Mojave, iOS 14.6 and iPadOS 14.6, iOS 12.5.4, Security Update 2021-003 Catalina, macOS Big Sur 11.4, watchOS 7.5. Processing a maliciously crafted certificate may lead to arbitrary code execution.
Affected: Apple ipados
Required Action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Exploitation References: https://support.apple.com/kb/HT212548
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://support.apple.com/en-us/HT212528https://support.apple.com/en-us/HT212529https://support.apple.com/en-us/HT212530https://support.apple.com/en-us/HT212531https://support.apple.com/en-us/HT212532https://support.apple.com/en-us/HT212533https://support.apple.com/en-us/HT212548https://support.apple.com/en-us/HT212528https://support.apple.com/en-us/HT212529https://support.apple.com/en-us/HT212530https://support.apple.com/en-us/HT212531https://support.apple.com/en-us/HT212532https://support.apple.com/en-us/HT212533https://support.apple.com/en-us/HT212548
2021-09-08
Published
Exploited in the wild