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CVE Record

CVE-2020-28873: Fluxbb 1.5.11 is affected by a denial of service (DoS) vulnerability by sending an extremely long password...

Fluxbb 1.5.11 is affected by a denial of service (DoS) vulnerability by sending an extremely long password via the user login form. When a long password is sent, the password hashing process will result in CPU and memory exhaustion on the server.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2020-28873 is a denial-of-service issue reported in FluxBB 1.5.11. A very long password submitted to the login form can cause expensive password hashing, exhausting server CPU and memory. For businesses, the main risk is forum or community-site unavailability, not data theft based on the available sources.

Executive priority

Treat as a near-term availability risk for internet-facing FluxBB 1.5.11 sites. Prioritize validation if the forum supports customers, operations, or revenue-facing services.

Technical view

The vulnerability is tied to long password handling during FluxBB 1.5.11 login. The CVE description says oversized password input can drive CPU and memory exhaustion during hashing. Public source data does not provide CVSS, CWE, patch version, or proof of active exploitation.

Likely exposure

Exposure is most likely where FluxBB 1.5.11 login pages are internet-accessible. Risk rises for small servers, shared hosting, or high-traffic sites without rate limits or request-size controls.

Exploitation context

The CVE is not listed as CISA KEV in the provided bundle, and no cited source states active exploitation. The issue appears remotely reachable through the normal login form, but sources do not provide exploit prevalence or observed attacks.

Researcher notes

Evidence is sparse: the CVE record identifies FluxBB 1.5.11 and long-password DoS behavior, while the Acunetix reference describes the general long-password hashing weakness. No official fix, CVSS score, or exploitation evidence is present in the supplied sources.

Mitigation direction

  • Confirm whether any public sites run FluxBB 1.5.11.
  • Check FluxBB/vendor guidance for fixed versions or official workarounds.
  • Apply conservative request-size or password-length limits at the application or edge.
  • Use rate limiting on login endpoints where supported.
  • Monitor CPU, memory, and login error spikes.

Validation and detection

  • Inventory FluxBB deployments and record exact versions.
  • Identify whether login pages are publicly reachable.
  • Review web server or WAF limits for oversized POST bodies.
  • Check monitoring for resource exhaustion around login requests.
  • Confirm any vendor-recommended update or configuration is applied.
Prepared
Confidence
medium
Sources
3

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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description · low confidence lookup

Credential and access behavior lookup

The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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cve · low confidence lookup

CVE-2020-28873 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
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.

0CVSS vectors
3Timeline events
1ADP providers
2Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

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