Security readout for executives and security teams
Plain-English summary
This is a denial-of-service flaw in Oracle WebLogic Server. An unauthenticated attacker who can reach the server over the T3 protocol can make WebLogic hang or repeatedly crash. The known impact is availability loss, not data theft or code execution, but exposed systems could face outage risk.
Executive priority
Treat as high priority for business-critical WebLogic services because unauthenticated network access can cause outages. Urgency rises sharply if T3 is exposed beyond tightly controlled internal networks.
Technical view
CVE-2021-35620 affects WebLogic Server 10.3.6.0.0, 12.1.3.0.0, 12.2.1.3.0, 12.2.1.4.0, and 14.1.1.0.0. Oracle describes it as remotely exploitable over T3 with no authentication, low complexity, no user interaction, and high availability impact. CVSS is 7.5.
Likely exposure
Exposure is most likely where affected WebLogic instances allow network access to T3 from untrusted networks, internet-facing segments, partner networks, or broad internal zones.
Exploitation context
The provided sources do not state active exploitation, and the bundle marks KEV as false. The attacker model is unauthenticated network access via T3. The stated outcome is hang or frequently repeatable crash causing complete denial of service.
Researcher notes
Evidence is limited to Oracle and CVE metadata. The record supports remote unauthenticated DoS via T3 only; it does not support confidentiality impact, integrity impact, code execution, or active exploitation claims.
Mitigation direction
- Identify all WebLogic Server instances and versions in scope.
- Review Oracle October 2021 CPU guidance for the vendor-supported fix path.
- Prioritize remediation where T3 is reachable from untrusted networks.
- Restrict T3 exposure to trusted paths where operationally feasible.
- Monitor affected services for repeated crashes or hangs.
Validation and detection
- Confirm deployed WebLogic versions against the affected version list.
- Verify whether T3 is reachable from internet, partner, or broad internal networks.
- Check patch records against Oracle October 2021 CPU guidance.
- Review monitoring for WebLogic hangs, restarts, or repeated crash patterns.
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-2021-35620 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
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary 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: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.