dbcve.org
FedoraOperating system · Fedoraproject

CVE-2023-27538

MEDIUM · 5.5 CVSS v3.1 Published 2023-03-30
Fix available
A fix is available. Upgrade to 8.0.0 or later.
See remediation →
57/100
Remediation priority · Elevated
Public exploit Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An authentication bypass vulnerability exists in libcurl prior to v8.0.0 where it reuses a previously established SSH connection despite the fact that an SSH option was modified, which should have prevented reuse. libcurl maintains a pool of previously used connections to reuse them for subsequent transfers if the configurations match. However, two SSH settings were omitted from the configuration check, allowing them to match easily, potentially leading to the reuse of an inappropriate connection.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FedoraOperating system
Affected:= 36
Debian LinuxOperating system
Affected:= 10.0
LibcurlApplication
Affected:>= 7.16.1, < 8.0.0
Active Iq Unified ManagerApplication
Affected:all versions
Clustered Data OntapApplication
Affected:= 9.0
Brocade Fabric Operating System FirmwareOperating system
Affected:all versions
H300s FirmwareOperating system
Affected:all versions
H500s FirmwareOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 8.0.0 or later
Fixed in 8.0.0
Recommended fix Moderate confidence

libcurl 8.0.0 or later (or vendor-specific patched versions for appliances)

  1. Identify the libcurl version currently installed using `curl --version` or checking package manager
  2. Update the system package repository to ensure latest packages are available
  3. Upgrade libcurl to version 8.0.0 or later using the distribution's package manager (e.g., `dnf update libcurl` for Fedora, `apt update && apt upgrade libcurl` for Debian)
  4. Verify the upgrade was successful by checking the new version with `curl --version`
  5. For embedded products or appliances (NetApp, Brocade, H300s/H500s), apply vendor-supplied firmware updates that include the libcurl 8.0.0 patch
Caveat Upgrading libcurl may introduce API/behavior changes; test in non-production environment first, especially for applications relying on specific curl behaviors

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-27538 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data