Security readout for executives and security teams
Plain-English summary
Some applications using Reactor Netty HttpClient could leak credentials when following a redirect to another domain. This requires explicit redirect-following configuration, so not every Reactor Netty deployment is exposed. The business risk is credential disclosure from affected application integrations.
Executive priority
Treat as moderate priority. Focus on applications that handle credentials in outbound HTTP calls, especially customer-facing services or integrations. There is no source evidence here of active exploitation, but credential leakage can create downstream account and data exposure.
Technical view
CVE-2020-5404 affects Reactor Netty HttpClient 0.9.x before 0.9.5 and 0.8.x before 0.8.16. If the client is explicitly configured to follow redirects, credentials may be sent during cross-domain redirects. The CVSS 3.0 score is 6.5 and maps to CWE-522.
Likely exposure
Exposure is likely limited to Java applications using Reactor Netty 0.8.x or 0.9.x HttpClient with redirect following enabled, especially where requests include credentials or tokens.
Exploitation context
The provided sources do not show KEV listing or active exploitation. Exploitability depends on an application using the affected client versions, enabling redirects, and handling a redirect to a different domain.
Researcher notes
Key conditions are affected Reactor Netty version and explicit redirect-following configuration. The source bundle names fixed version thresholds but provides limited operational detail. CVSS indicates high confidentiality impact, high attack complexity, required low privilege, and user interaction.
Mitigation direction
- Upgrade Reactor Netty 0.9.x to 0.9.5 or later.
- Upgrade Reactor Netty 0.8.x to 0.8.16 or later.
- Review vendor guidance for any branch-specific remediation notes.
- Avoid sending credentials across redirects unless explicitly intended.
Validation and detection
- Inventory applications and dependency trees for Reactor Netty 0.8.x or 0.9.x.
- Confirm whether HttpClient redirect following is explicitly enabled.
- Review outbound integrations that include Authorization headers, tokens, or credentials.
- Verify upgraded builds no longer resolve affected Reactor Netty versions.
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-522: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. 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-2020-5404 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 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:H/PR:L/UI:R/S:C/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:3.0/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:L/A:N1.34.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.5MediumVector: CVSS:3.0/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://pivotal.io/security/cve-2020-5404CVE reference · x_refsource_CONFIRM
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.
Insufficiently Protected Credentials
Insufficiently Protected Credentials represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.