Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NSummary
CVE-2021-31010 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Apple Mac Os X. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 11% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
A deserialization issue tracked as CVE-2021-31010 and assigned CWE-502 was present in multiple Apple operating systems. The flaw stems from insufficient validation during deserialization and could allow improper handling of serialized data. It affected iOS, iPadOS, macOS Catalina, macOS Big Sur, and watchOS prior to the releases that addressed it.
An attacker could exploit the vulnerability over a network without authentication or user interaction to enable a sandboxed process to bypass sandbox restrictions, resulting in unauthorized modification of data as reflected in the CVSS vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
The issue is resolved in Security Update 2021-005 Catalina, iOS 12.5.5, iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6, and watchOS 7.6.2, as detailed in the corresponding Apple security advisories.
Apple stated that it was aware of reporting indicating the vulnerability may have been actively exploited in the wild at the time the fixes were released.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-17927
Vulnerability Data
A deserialization issue was addressed through improved validation. This issue is fixed in Security Update 2021-005 Catalina, iOS 12.5.5, iOS 14.8 and iPadOS 14.8, macOS Big Sur 11.6, watchOS 7.6.2. A sandboxed process may be able to circumvent sandbox restrictions.…
more
Apple was aware of a report that this issue may have been actively exploited at the time of release..
- CWE(s)
- KEV Date Added
- 25 August 2022
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.
Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.
Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.
Validates or rejects untrusted serialized data before deserialization occurs.
Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.
Integrity verification of serialized information can detect tampering before deserialization occurs.
Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
PR.PS-02 addresses only post-deployment updates/patching and cannot prevent introduction of unsafe deserialization code, yet it can remediate some instances when the flaw exists in outdated libraries or components.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing includes validation of deserialization routines and the use of untrusted data, reducing the likelihood that unsafe object reconstruction will be deployed.
Requiring vetted libraries, regular updates and SAST before release reduces the likelihood that deserialization logic will accept and act on attacker-controlled serialized objects.
Regular scanning of third-party libraries and timely patching reduce the likelihood that unsafe deserialization vulnerabilities remain active.
Mandatory malware scanning of data received over networks or storage media intercepts malicious serialized payloads before they are deserialized by the target application.