Fiber has Insecure CORS Configuration, Allowing Wildcard Origin with Credentials
gofiber · fiber
Official source article: GitHub GHSA-FMG4-X8PW-HJHG ↗. Check the applicable product and release in the original source.
9.4CriticalCVSS 3.1
Recommended action
Within 72 hours
Critical technical impact with a remotely reachable, unauthenticated path and a public exploit reference; no CISA KEV confirmation is currently recorded.
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Evidence used
No CISA KEV confirmation is currently recorded.
A structured source references public exploit or proof-of-concept material.
The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
EPSS is 0.66% for the current model date.
Compensating controls
Validate the affected product branch and deploy the verified fixed release.
Restrict the affected network interface to trusted sources where business-safe.
Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
Confirm that the asset runs gofiber fiber and falls inside the recorded affected range.
Verify the installed build against the product-specific fixed version after deployment.
Validate exposure, authentication requirements and compensating controls in the actual environment.
Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Open-source package ranges1 source-attributed range
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.
Official European source
ENISA European Vulnerability Database
Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.
1 current
ENISA EUVD identifier
EUVD-2024-0629
No EUVD known-exploited evidence
ENISA has published the identifier mapping but no EUVD description has been stored yet.
EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 72 hours
Critical technical impact with a remotely reachable, unauthenticated path and a public exploit reference; no CISA KEV confirmation is currently recorded.
Patch available
01
What, why and how
Fiber is a web framework written in go. Prior to version 2.52.1, the CORS middleware allows for insecure configurations that could potentially expose the application to multiple CORS-related vulnerabilities. Specifically, it allows setting the Access-Control-Allow-Origin header to a wildcard (`*`) while also having the Access-Control-Allow-Credentials set to true, which goes against recommended security best practices. The impact of this misconfiguration is high as it can lead to unauthorized access to sensitive user data and expose the system to various types of attacks listed in the PortSwigger article linked in the references. Version 2.52.1 contains a patch for this issue. As a workaround, users may manually validate the CORS configurations in their implementation to ensure that they do not allow a wildcard origin when credentials are enabled. The browser fetch api, as well as browsers and utilities that enforce CORS policies, are not affected by this.
What
Fiber is a web framework written in go. Prior to version 2.52.1, the CORS middleware allows for insecure configurations that could potentially expose the application to multiple CORS-related vulnerabilities. Specifically, it allows setting the Access-Control-Allow-Origin header to a wildcard (`*`) while also having the Access-Control-Allow-Credentials set to true, which goes against recommended security best practices. The impact of this misconfiguration is high as it can lead to unauthorized access to sensitive user data and expose the system to various types of attacks listed in the PortSwigger article linked in the references. Version 2.52.1 contains a patch for this issue. As a workaround, users may manually validate the CORS configurations in their implementation to ensure that they do not allow a wildcard origin when credentials are enabled. The browser fetch api, as well as browsers and utilities that enforce CORS policies, are not affected by this.
Why
The product does not properly verify that the source of data or communication is valid.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
Fiber is a web framework written in go. Prior to version 2.52.1, the CORS middleware allows for insecure configurations that could potentially expose the application to multiple CORS-related vulnerabilities. Specifically, it allows setting the Access-Control-Allow-Origin header to a wildcard (`*`) while also having the Access-Control-Allow-Credentials set to true, which goes against recommended security best practices. The impact of this misconfiguration is high as it can lead to unauthorized access to sensitive user data and expose the system to various types of attacks listed in the PortSwigger article linked in the references. Version 2.52.1 contains a patch for this issue. As a workaround, users may manually validate the CORS configurations in their implementation to ensure that they do not allow a wildcard origin when credentials are enabled. The browser fetch api, as well as browsers and utilities that enforce CORS policies, are not affected by this.
Why
The product does not properly verify that the source of data or communication is valid.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No confirmed evidence
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.Reference recorded
A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
Likely attack path
a network path → Origin Validation Error → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-346: Origin Validation Error. The product does not properly verify that the source of data or communication is valid.
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.ALowAvailability impact: A successful attack can cause a limited loss.
Post-exploitation / living off the land
Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2024-0629Official EUVD mapping
0 linked advisory records.
Official EUVD record ↗Cyber Security Agency of Singapore · English · CSA-SB-20240228Security Bulletin 28 Feb 2024
The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 28 Feb 2024, published on 28 February 2024. Open the linked bulletin for the product, severity and reference information published in that issue.
Official advisory ↗JVN iPedia · Japanese · JVNDB-2024-018230Gofiber の Go 用 Fiber における同一生成元ポリシー違反に関する脆弱性
Operational remediation based on structured source evidence.
Status ?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 21 Feb 2024 · Last source change 26 Aug 2024, 14:39 UTC · CWE-346 · Origin Validation Error
CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source ?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2024-0629
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.