Security readout for executives and security teams
Plain-English summary
CVE-2021-35539 is a denial-of-service flaw in Oracle Solaris 11 filesystem handling. A low-privileged user who can log on to a Solaris system could cause the operating system to hang or crash repeatedly, potentially disrupting dependent services.
Executive priority
Treat this as a moderate operational resilience issue. It is not described as remote code execution, but affected Solaris 11 systems could be crashed by a low-privileged logged-in attacker.
Technical view
Oracle describes a locally exploitable Solaris 11 filesystem vulnerability with low attack complexity, low privileges required, and no user interaction. The impact is availability-only, with complete DoS possible and scope marked changed. CVSS v3.1 score is 6.5.
Likely exposure
Exposure is most relevant for organizations running Oracle Solaris 11 where non-administrative users, service accounts, tenants, or contractors can log on to affected infrastructure.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. Exploitation requires local logon access, so internet-facing exposure is indirect unless an attacker already has credentials or another foothold.
Researcher notes
The source bundle does not include CWE details or root-cause specifics beyond the Solaris filesystem component. Avoid assuming affected versions beyond Solaris 11 or claiming exploit availability without new evidence.
Mitigation direction
- Review Oracle's October 2021 CPU guidance for Solaris 11.
- Apply applicable Oracle Solaris security updates through approved maintenance processes.
- Restrict Solaris logon access to trusted users and required service accounts.
- Prioritize systems supporting critical workloads or shared user access.
Validation and detection
- Inventory Oracle Solaris 11 systems across production and shared environments.
- Confirm each host's patch status against Oracle's October 2021 CPU.
- Review which low-privileged accounts can log on to Solaris hosts.
- Check monitoring for unexplained Solaris hangs or repeat crashes.
- Document dependent applications that would be affected by Solaris downtime.
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.
CVE-2021-35539 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
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
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:L/PR:L/UI:N/S:C/C:N/I:N/A:H24Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.oracle.com/security-alerts/cpuoct2021.htmlCVE 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.