Security readout for executives and security teams
Plain-English summary
CVE-2021-22552 is a memory overread in Google Asylo secure-enclave code. A local, low-privileged attacker interacting with affected enclave messaging could read sensitive memory from inside the enclave. Business urgency depends on whether Asylo is used in production enclave workloads.
Executive priority
Treat this as a targeted confidentiality risk for enclave-backed systems, not a broad internet-facing emergency. Prioritize remediation if Asylo protects sensitive keys, credentials, or regulated data in production.
Technical view
The flaw is CWE-126 in Asylo MessageReader/sysno handling. The CVE says an untrusted syscall number can bypass validation and permit memory reads from the secure enclave. CVSS 3.1 is 5.3 with local access, high complexity, low privileges, high confidentiality impact, and low integrity impact.
Likely exposure
Exposure is likely limited to organizations using Google Asylo in enclave-based applications, especially versions described as up to 0.6.1. The bundle title mentions 0.6.2, so version scoping should be confirmed against the vendor commit and deployed dependency records.
Exploitation context
The provided sources do not show active exploitation, and KEV is false. Exploitation requires local access, low privileges, no user interaction, and high attack complexity. The main concern is confidentiality loss from enclave memory, not remote takeover.
Researcher notes
Evidence is concise and partly inconsistent: the title names Asylo 0.6.2, while the description says versions up to 0.6.1 and recommends 0.6.3 or the linked commit. Validate exact affected revisions before declaring scope.
Mitigation direction
- Update Asylo to 0.6.3 or a version containing the referenced commit.
- Rebuild and redeploy enclave applications after updating the Asylo dependency.
- Limit local users and processes that can interact with affected enclave services until upgraded.
- Check Google Asylo guidance if version applicability remains unclear.
Validation and detection
- Inventory applications and images that include Google Asylo.
- Confirm deployed Asylo versions against 0.6.3 or the referenced fixed commit.
- Review build manifests for pinned Asylo revisions older than the fix.
- Prioritize validation for systems processing secrets inside enclaves.
- Confirm no production enclave workloads still use affected Asylo builds.
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-126: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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-2021-22552 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
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/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.
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:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N14.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/google/asylo/commit/90d7619e9dd99bcdb6cd28c7649d741d254d9a1aCVE reference · x_refsource_MISC
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.
Buffer Over-read
Buffer Over-read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.