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01 Record

CVE-2023-27538

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

HighPUBLISHEDCNA: hackerone
CNA base score7.7 CVSS v3.xCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

02 Description

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

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • 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
1.45% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 72.8% of scored records. A rank, not a probability.
NVD base score
5.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD analysis status
Modified. NVD last modified this record on 2026-10-14.
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 22:46Z14 DAYS AGO
Reserved
2023-03-02
Assigning CNA
hackerone
Record state
PUBLISHED
Severity
High (CVSS 7.7)
CNA CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Weaknesses
  • CWE-305Authentication Bypass by Primary WeaknessBase
  • CWE-287Improper AuthenticationClass
Data version
5.2
Document digest
3e5f77a3e63224846feb83117206e9c967ede21bd870d6438c5012a6c281fefe

05 Affected products

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

06 References

07 Fixed in

AlmaLinux 9

  • curl
    Fixed in 7.76.1-26.el9
  • curl-minimal
    Fixed in 7.76.1-26.el9
  • libcurl
    Fixed in 7.76.1-26.el9
  • libcurl-devel
    Fixed in 7.76.1-26.el9
  • libcurl-minimal
    Fixed in 7.76.1-26.el9

Source: 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 7.76.1-26.el9
  • curl-minimal
    Fixed in 7.76.1-26.el9
  • libcurl
    Fixed in 7.76.1-26.el9
  • libcurl-devel
    Fixed in 7.76.1-26.el9
  • libcurl-minimal
    Fixed in 7.76.1-26.el9

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.

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.