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CVE Record

CVE-2021-20354: IBM WebSphere Application Server 8.0, 8.5, and 9.0 could allow a remote attacker to traverse directories.

IBM WebSphere Application Server 8.0, 8.5, and 9.0 could allow a remote attacker to traverse directories. An attacker could send a specially-crafted URL request containing "dot dot" sequences (/../) to view arbitrary files on the system. IBM X-Force ID: 194883.

MediumCVSS 5.9Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

IBM WebSphere Application Server 8.0, 8.5, and 9.0 has a directory traversal flaw that could let a remote attacker read arbitrary files. The main business risk is exposure of sensitive files from affected servers, not service disruption or file tampering based on the supplied CVSS vector.

Executive priority

Handle as a moderate-priority confidentiality issue. Prioritize exposed or sensitive WebSphere servers, but the supplied evidence does not justify emergency treatment absent local exposure or additional threat intelligence.

Technical view

The vulnerability is a network-reachable directory traversal issue using parent-directory sequences in specially crafted URL requests. CVSS 3.0 is 5.9 with high confidentiality impact, no integrity or availability impact, no privileges, no user interaction, and high attack complexity.

Likely exposure

Exposure is most likely where IBM WebSphere Application Server 8.0, 8.5, or 9.0 is reachable by users or the internet. Systems hosting sensitive configuration, application, or credential-adjacent files deserve priority review.

Exploitation context

The supplied bundle does not show CISA KEV listing or confirmed active exploitation. IBM describes a remote attacker scenario, and the CVSS vector marks exploit maturity as unproven, so treat this as credible but not confirmed exploited from these sources.

Researcher notes

Key constraints are affected versions 8.0, 8.5, and 9.0, high attack complexity, unauthenticated network reachability, and confidentiality-only impact. Public sources in the bundle do not provide CWE mapping, detailed patch levels, or confirmed exploitation.

Mitigation direction

  • Identify all WebSphere Application Server 8.0, 8.5, and 9.0 instances.
  • Review IBM advisory node 6415959 for the official remediation.
  • Apply IBM-provided fixes or supported updates for affected deployments.
  • Restrict external access to affected WebSphere endpoints until remediated.
  • Prioritize systems storing sensitive files or exposed to untrusted networks.

Validation and detection

  • Confirm WebSphere product versions and fix levels against IBM guidance.
  • Map internet-facing and partner-facing WebSphere endpoints.
  • Review access logs for suspicious directory traversal patterns.
  • Verify affected servers no longer expose unintended filesystem content.
  • Document compensating controls for systems awaiting remediation.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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

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CVE-2021-20354 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.9 (3.0)
Known Exploited
No
Published

Vector: CVSS:3.0/I:N/UI:N/A:N/AV:N/PR:N/AC:H/S:U/C:H/RL:O/RC:C/E:U

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
5.9CVSS 3.0MediumCVSS:3.0/I:N/UI:N/A:N/AV:N/PR:N/AC:H/S:U/C:H/RL:O/RC:C/E:U2.23.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.0 score

5.9Medium
CVSS 3.0 vector shape for CVE-2021-20354Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.0/I:N/UI:N/A:N/AV:N/PR:N/AC:H/S:U/C:H/RL:O/RC:C/E:U

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
IBMWebSphere Application Server8.0, 8.5, 9.0Listed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.