CVE-2025-27111: Rack Escape Sequence Injection Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-8cgq-6mh2-7j6v
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CWE-117 CWE-93
Published
Advisory Summary

CVE-2025-27111 is a MODERATE escape sequence injection vulnerability vulnerability (CWE-117: Improper Output Neutralization for Logs) affecting Rack libraries in the RubyGems ecosystem. The issue involves escape sequence injection vulnerability in rack lead to possible log injection. Remediation is available by upgrading affected packages to version 2.2.12, 3.0.13, 3.1.11.

CVE-2025-27111 at a Glance

CVE Identifier CVE-2025-27111
GHSA Identifier GHSA-8cgq-6mh2-7j6v
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-117: Improper Output Neutralization for Logs
Affected Product Rack
Package Ecosystem RubyGems
Published Date
Last Updated

How to Fix CVE-2025-27111

To remediate this vulnerability, upgrade all affected Rack dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

rack fixed: 2.2.12 
Upgrade rack to 2.2.12
rack fixed: 3.0.13 
Upgrade rack to 3.0.13
rack fixed: 3.1.11 
Upgrade rack to 3.1.11
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for rack

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-27111, inspect your project dependencies for Rack:

inspect dependencies for rack

Analyze the terminal output to locate any version of Rack in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.2.12), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-117: Improper Output Neutralization for Logs, where the product constructs a log message from external input, but it does not neutralize or incorrectly neutralizes special elements when the message is written to a log file. In Rack, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Summary `Rack::Sendfile` can be exploited by crafting input that includes newline characters to manipulate log entries. ## Details The `Rack::Sendfile` middleware logs unsanitized header values from the `X-Sendfile-Type` header. An attacker can exploit this by injecting escape sequences (such as newline characters) into the header, resulting in log injection. ## Impact This vulnerability can distort log files, obscure attack traces, and complicate security auditing. ## Mitigation - Update to the latest version of Rack, or - Remove usage of `Rack::Sendfile`.

CVE-2025-27111 Affected Rack Versions

3 component(s)
Fixed Versions:
2.2.123.0.133.1.11
Product / Package Ecosystem Affected Versions Fixed Version
rack
gem/rack
RubyGems
< 2.2.12
2.2.12
rack
gem/rack
RubyGems
≥ 3.0
< 3.0.13
3.0.13
rack
gem/rack
RubyGems
≥ 3.1
< 3.1.11
3.1.11

References

GitHub Advisory / Wiki ADVISORY
https://github.com/rack/rack/security/advisories/GHSA-8cgq-6mh2-7j6v
NVD — CVE-2025-27111 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-27111
Security Fix Commit FIX COMMIT
https://github.com/rack/rack/commit/803aa221e8302719715e224f4476e438f2531a53
Security Fix Commit FIX COMMIT
https://github.com/rack/rack/commit/aeac570bb8080ca7b53b7f2e2f67498be7ebd30b
Security Fix Commit FIX COMMIT
https://github.com/rack/rack/commit/b13bc6bfc7506aca3478dc5ac1c2ec6fc53f82a3
Rack Source Repository REPOSITORY
https://github.com/rack/rack
Rack Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2025-27111.yml
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2025/03/msg00016.html

Frequently Asked Questions

What is CVE-2025-27111?
CVE-2025-27111 is a security vulnerability in Rack involving Escape Sequence Injection vulnerability in Rack lead to Possible Log Injection under CWE-117: Improper Output Neutralization for Logs.
Which Rack versions are affected?
Affected versions include releases prior to 2.2.12, 3.0.13, 3.1.11 across affected packages: rack.
What version fixes CVE-2025-27111?
Upgrading to 2.2.12, 3.0.13, 3.1.11 (or the latest patched release for your respective branch) resolves the vulnerability.
Is rack affected?
Yes, rack is affected in releases prior to 2.2.12, 3.0.13, 3.1.11. Upgrade your dependency to 2.2.12, 3.0.13, 3.1.11 or later.
What CWE is associated with CVE-2025-27111?
CVE-2025-27111 is classified under CWE-117: Improper Output Neutralization for Logs (The product constructs a log message from external input, but it does not neutralize or incorrectly neutralizes special elements when the message is written to a log file.).
How can I check RubyGems dependencies for CVE-2025-27111?
Run the dependency tree command: 'inspect dependencies for rack'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8cgq-6mh2-7j6v",
  "modified" : "2025-11-04T16:55:18Z",
  "published" : "2025-03-04T15:27:06Z",
  "aliases" : [ "CVE-2025-27111" ],
  "summary" : "Escape Sequence Injection vulnerability in Rack lead to Possible Log Injection",
  "details" : "## Summary\n\n`Rack::Sendfile` can be exploited by crafting input that includes newline characters to manipulate log entries.\n\n## Details\n\nThe `Rack::Sendfile` middleware logs unsanitized header values from the `X-Sendfile-Type` header. An attacker can exploit this by injecting escape sequences (such as newline characters) into the header, resulting in log injection.\n\n## Impact\n\nThis vulnerability can distort log files, obscure attack traces, and complicate security auditing.\n\n## Mitigation\n\n- Update to the latest version of Rack, or\n- Remove usage of `Rack::Sendfile`.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ {
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    },
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    } ]
  }, {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "rack"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0"
      }, {
        "fixed" : "3.0.13"
      } ]
    } ]
  }, {
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    } ]
  } ],
  "references" : [ {
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  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-27111"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rack/rack/commit/803aa221e8302719715e224f4476e438f2531a53"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rack/rack/commit/aeac570bb8080ca7b53b7f2e2f67498be7ebd30b"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rack/rack/commit/b13bc6bfc7506aca3478dc5ac1c2ec6fc53f82a3"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/rack/rack"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2025-27111.yml"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2025/03/msg00016.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-117", "CWE-93" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-03-04T15:27:06Z",
    "nvd_published_at" : "2025-03-04T16:15:40Z"
  }
}