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01 Record

CVE-2023-27539

There is a denial of service vulnerability in the header parsing component of Rack.

MediumPUBLISHEDCNA: hackerone
CNA base score5.3 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
View raw JSON

02 Description

There is a denial of service vulnerability in the header parsing component of Rack.

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
1.05% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 63.8% of scored records. A rank, not a probability.
NVD base score
5.3 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD analysis status
Analyzed. NVD last modified this record on 2026-06-17.
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
2025-01-09 00:33Z1 YR AGO
Last updated
2025-01-09 21:24Z1 YR AGO
Reserved
2023-03-02
Assigning CNA
hackerone
Record state
PUBLISHED
Severity
Medium (CVSS 5.3)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weaknesses
  • CWE-1333Inefficient Regular Expression ComplexityBase
Data version
5.1
Document digest
2e377076310be44be7fa03ff7d54d46a9d7410475307109f900fdf301a0631ea

05 Affected products

VendorProductVersionsPlatforms
RailsRack2.2.6.4 to < 2.2.6.4, 3.0.6.1 to < 3.0.6.1—

06 References

07 Fixed in

AlmaLinux 8

  • pcs
    Fixed in 0.10.15-4.el8_8.1.alma
  • pcs-snmp
    Fixed in 0.10.15-4.el8_8.1.alma

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

AlmaLinux 9

  • pcs
    Fixed in 0.11.4-7.el9_2
  • pcs-snmp
    Fixed in 0.11.4-7.el9_2

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

CloudLinux 8

  • pcs
    Fixed in 0.10.15-4.el8_8.1.alma
  • pcs-snmp
    Fixed in 0.10.15-4.el8_8.1.alma

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

  • pcs
    Fixed in 0.11.4-7.el9_2
  • pcs-snmp
    Fixed in 0.11.4-7.el9_2

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

  • ruby-rack
    Fixed in 2.2.6.4-1

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

Debian 13

  • ruby-rack
    Fixed in 2.2.6.4-1

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

Debian 14

  • ruby-rack
    Fixed in 2.2.6.4-1

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

Ubuntu 22.04 LTS

  • ruby-rack
    Fixed in 2.1.4-5ubuntu1.1

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

Ubuntu Pro 14.04 LTS

  • ruby-rack
    Fixed in 1.5.2-3+deb8u3ubuntu1~esm7
    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

  • ruby-rack
    Fixed in 1.6.4-3ubuntu0.2+esm5
    Available with Ubuntu Pro: 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 18.04 LTS

  • ruby-rack
    Fixed in 1.6.4-4ubuntu0.2+esm5
    Available with Ubuntu Pro: 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 20.04 LTS

  • ruby-rack
    Fixed in 2.0.7-2ubuntu0.1+esm4
    Available with Ubuntu Pro: 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 22.04 LTS

  • ruby-rack
    Fixed in 2.1.4-5ubuntu1+esm4
    Available with Ubuntu Pro: 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.