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CVE Record

CVE-2021-29726: IBM Sterling Secure Proxy 6.0.3 and IBM Secure External Authentication Server 6.0.3 does not properly ensur...

IBM Sterling Secure Proxy 6.0.3 and IBM Secure External Authentication Server 6.0.3 does not properly ensure that a certificate is actually associated with the host due to improper validation of certificates. IBM X-Force ID: 201104.

MediumCVSS 5.3Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This flaw affects IBM Sterling Secure Proxy 6.0.3 and IBM Secure External Authentication Server 6.0.3. The software may accept a certificate without properly confirming it belongs to the expected host. That can weaken trust decisions and allow integrity-impacting security bypass scenarios, but the provided sources do not show data theft, outage impact, or active exploitation.

Executive priority

Address in the normal vulnerability remediation cycle, with higher priority for internet-facing or partner-facing deployments. Urgency is moderate because the issue is network-reachable but only low integrity impact is documented and no active exploitation is cited.

Technical view

CVE-2021-29726 is improper certificate validation involving host association. The CVSS 3.0 vector is network-accessible, low complexity, no privileges, no user interaction, with low integrity impact only. IBM X-Force tracks it as ID 201104. The source bundle names only version 6.0.3 for both affected IBM products.

Likely exposure

Exposure is likely limited to environments running IBM Sterling Secure Proxy 6.0.3 or IBM Secure External Authentication Server 6.0.3, especially where these systems validate remote certificates for trusted connections.

Exploitation context

The bundle marks KEV as false and CVSS exploit maturity as unproven. No cited source in the bundle states active exploitation. Treat this as a trust-validation weakness that could matter most in exposed or security-sensitive transfer and authentication paths.

Researcher notes

The public bundle does not include detailed attack prerequisites, affected configuration conditions, or fixed build numbers. Avoid assuming broader IBM Sterling versions are affected. Use IBM support pages and X-Force entry as authoritative follow-up sources.

Mitigation direction

  • Check IBM advisories for the vendor-specified fix or mitigation.
  • Prioritize affected 6.0.3 deployments handling external or partner traffic.
  • Confirm certificate validation policies require host association.
  • Plan remediation through normal IBM-supported maintenance channels.

Validation and detection

  • Inventory deployments of both affected IBM products.
  • Confirm whether any instance runs version 6.0.3.
  • Review IBM advisory applicability against installed builds.
  • Verify certificates match expected host identities in relevant integrations.
Prepared
Confidence
medium
Sources
5

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-2021-29726 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
5.3 (3.0)
Known Exploited
No
Published

Vector: CVSS:3.0/S:U/AC:L/UI:N/PR:N/A:N/AV:N/C:N/I:L/RC:C/RL:O/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
4Source 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
5.3CVSS 3.0MediumCVSS:3.0/S:U/AC:L/UI:N/PR:N/A:N/AV:N/C:N/I:L/RC:C/RL:O/E:U3.91.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.0 score

5.3Medium
CVSS 3.0 vector shape for CVE-2021-29726Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.0/S:U/AC:L/UI:N/PR:N/A:N/AV:N/C:N/I:L/RC:C/RL:O/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
IBMSecure External Authentication Server6.0.3Listed
IBMSterling Secure Proxy6.0.3Listed
Weakness

CWE details

No CWE listed

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