Security readout for executives and security teams
Plain-English summary
CVE-2021-31010 is an Apple deserialization flaw that could let a sandboxed process bypass sandbox restrictions. Apple fixed it in 2021 updates for Catalina, Big Sur, iOS/iPadOS, and watchOS. Apple reported possible active exploitation at release, and CISA lists it in KEV, so unpatched legacy Apple devices deserve priority.
Executive priority
Treat this as a high-priority legacy Apple patching issue. The business urgency comes from confirmed KEV status and Apple’s exploitation warning, not from public exploit details. Focus on finding unpatched devices and closing support gaps.
Technical view
The flaw is CWE-502 deserialization with improved validation as the stated fix. The CVSS 3.1 vector is 7.5 high, network-reachable, low-complexity, no privileges or user interaction, with high integrity impact. Public sources do not provide exploit mechanics or a complete affected-version matrix.
Likely exposure
Exposure is most likely on Apple systems that have not received the listed fixed releases: Security Update 2021-005 Catalina, iOS 12.5.5, iOS/iPadOS 14.8, macOS Big Sur 11.6, and watchOS 7.6.2. The provided affected list is incomplete and version-unspecified.
Exploitation context
Active exploitation is supported by Apple’s statement that the issue may have been actively exploited at release and by CISA KEV listing. The source bundle does not identify the attacker, campaign, exploit chain, or whether exploitation remains widespread.
Researcher notes
Public evidence supports sandbox escape risk through unsafe deserialization and validation hardening as the fix. Affected-version precision is limited in the provided data. Avoid assuming exploit paths, impacted components, or compensating controls beyond Apple updates and vendor guidance.
Mitigation direction
- Apply the Apple fixed releases or later supported updates.
- Prioritize unmanaged, legacy, and internet-connected Apple devices.
- Check Apple guidance for any platform-specific remediation details.
- Retire or isolate devices that cannot receive vendor updates.
Validation and detection
- Inventory macOS, iOS, iPadOS, and watchOS versions.
- Confirm devices meet or exceed the fixed Apple release levels.
- Check vulnerability management tools for CVE-2021-31010 detections.
- Review CISA KEV tracking for remediation deadlines or policy impact.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-502: Code execution behavior lookup
Code execution and unsafe deserialization weaknesses often justify reviewing execution behavior and process telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-31010 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://support.apple.com/en-us/HT212804CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212805CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212807CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212806CVE reference · x_refsource_MISC
- https://support.apple.com/en-us/HT212824CVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31010CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Deserialization of Untrusted Data
Deserialization of Untrusted Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.