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01 Record

CVE-2023-27535

An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created

MediumPUBLISHEDCNA: hackerone
CNA base score5.9 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

02 Description

An authentication bypass vulnerability exists in libcurl <8.0.0 in the FTP connection reuse feature that can result in wrong credentials being used during subsequent transfers. Previously created

03 Exploitation and scoring

Exploitation
Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
SSVC decision
  • ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
1.80% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 78.1% of scored records. A rank, not a probability.
NVD base score
5.9 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD analysis status
Modified. NVD last modified this record on 2026-10-24.
Red Hat severity
Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2023-03-30 00:00Z3 YR AGO
Last updated
2026-10-14 22:41Z14 DAYS AGO
Reserved
2023-03-02
Assigning CNA
hackerone
Record state
PUBLISHED
Severity
Medium (CVSS 5.9)
CNA CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weaknesses
  • CWE-305Authentication Bypass by Primary WeaknessBase
  • CWE-287Improper AuthenticationClass
Data version
5.2
Document digest
728726e7db3cb3a61c541128ff8a81474ad6e402312e398fae0812d7dd90c81a

05 Affected products

VendorProductVersionsPlatforms
n/ahttps://github.com/curl/curlFixed in 8.0.0—

06 References

07 Fixed in

AlmaLinux 8

  • curl
    Fixed in 7.61.1-30.el8_8.2
  • libcurl
    Fixed in 7.61.1-30.el8_8.2
  • libcurl-devel
    Fixed in 7.61.1-30.el8_8.2
  • libcurl-minimal
    Fixed in 7.61.1-30.el8_8.2

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

AlmaLinux 9

  • curl
    Fixed in 7.76.1-23.el9_2.1
  • curl-minimal
    Fixed in 7.76.1-23.el9_2.1
  • libcurl
    Fixed in 7.76.1-23.el9_2.1
  • libcurl-devel
    Fixed in 7.76.1-23.el9_2.1
  • libcurl-minimal
    Fixed in 7.76.1-23.el9_2.1

Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 8

  • curl
    Fixed in 7.61.1-30.el8_8.2
  • libcurl
    Fixed in 7.61.1-30.el8_8.2
  • libcurl-devel
    Fixed in 7.61.1-30.el8_8.2
  • libcurl-minimal
    Fixed in 7.61.1-30.el8_8.2

Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

CloudLinux 9

  • curl
    Fixed in 7.76.1-23.el9_2.1
  • curl-minimal
    Fixed in 7.76.1-23.el9_2.1
  • libcurl
    Fixed in 7.76.1-23.el9_2.1
  • libcurl-devel
    Fixed in 7.76.1-23.el9_2.1
  • libcurl-minimal
    Fixed in 7.76.1-23.el9_2.1

Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.

Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.

Debian 12

  • curl
    Fixed in 7.88.1-7

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • curl
    Fixed in 7.88.1-7

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • curl
    Fixed in 7.88.1-7

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 18.04 LTS

  • curl
    Fixed in 7.58.0-2ubuntu3.24

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • curl
    Fixed in 7.68.0-1ubuntu2.18

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • curl
    Fixed in 7.81.0-1ubuntu1.10

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 14.04 LTS

  • curl
    Fixed in 7.35.0-1ubuntu2.20+esm15
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 16.04 LTS

  • curl
    Fixed in 7.47.0-1ubuntu2.19+esm8
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.