CVE-2023-29383 (GCVE-0-2023-29383)

Vulnerability from cvelistv5 – Published: 2023-04-14 00:00 – Updated: 2025-11-03 19:28
VLAI
Summary
In Shadow 4.13, it is possible to inject control characters into fields provided to the SUID program chfn (change finger). Although it is not possible to exploit this directly (e.g., adding a new user fails because \n is in the block list), it is possible to misrepresent the /etc/passwd file when viewed. Use of \r manipulations and Unicode characters to work around blocking of the : character make it possible to give the impression that a new user has been added. In other words, an adversary may be able to convince a system administrator to take the system offline (an indirect, social-engineered denial of service) by demonstrating that "cat /etc/passwd" shows a rogue user account.
Severity
No CVSS data available.
CWE
  • n/a
Assigner
References
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-03T19:28:12.823Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/shadow-maint/shadow/pull/687"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/"
          },
          {
            "url": "https://lists.debian.org/debian-lts-announce/2025/04/msg00026.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2023-29383",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-02-06T21:21:27.050601Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-125",
                "description": "CWE-125 Out-of-bounds Read",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-02-06T21:23:31.283Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In Shadow 4.13, it is possible to inject control characters into fields provided to the SUID program chfn (change finger). Although it is not possible to exploit this directly (e.g., adding a new user fails because \\n is in the block list), it is possible to misrepresent the /etc/passwd file when viewed. Use of \\r manipulations and Unicode characters to work around blocking of the : character make it possible to give the impression that a new user has been added. In other words, an adversary may be able to convince a system administrator to take the system offline (an indirect, social-engineered denial of service) by demonstrating that \"cat /etc/passwd\" shows a rogue user account."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "n/a",
              "lang": "en",
              "type": "text"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-04-14T00:00:00.000Z",
        "orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
        "shortName": "mitre"
      },
      "references": [
        {
          "url": "https://github.com/shadow-maint/shadow/pull/687"
        },
        {
          "url": "https://github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d"
        },
        {
          "url": "https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797"
        },
        {
          "url": "https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca",
    "assignerShortName": "mitre",
    "cveId": "CVE-2023-29383",
    "datePublished": "2023-04-14T00:00:00.000Z",
    "dateReserved": "2023-04-05T00:00:00.000Z",
    "dateUpdated": "2025-11-03T19:28:12.823Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2023-29383",
      "date": "2026-05-30",
      "epss": "0.00053",
      "percentile": "0.16976"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2023-29383\",\"sourceIdentifier\":\"cve@mitre.org\",\"published\":\"2023-04-14T22:15:07.680\",\"lastModified\":\"2025-11-03T20:16:01.283\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In Shadow 4.13, it is possible to inject control characters into fields provided to the SUID program chfn (change finger). Although it is not possible to exploit this directly (e.g., adding a new user fails because \\\\n is in the block list), it is possible to misrepresent the /etc/passwd file when viewed. Use of \\\\r manipulations and Unicode characters to work around blocking of the : character make it possible to give the impression that a new user has been added. In other words, an adversary may be able to convince a system administrator to take the system offline (an indirect, social-engineered denial of service) by demonstrating that \\\"cat /etc/passwd\\\" shows a rogue user account.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N\",\"baseScore\":3.3,\"baseSeverity\":\"LOW\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.8,\"impactScore\":1.4}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-74\"}]},{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-125\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:shadow_project:shadow:4.13:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"79B0C1D0-9CF5-451D-B3B3-750B64FD7575\"}]}]}],\"references\":[{\"url\":\"https://github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d\",\"source\":\"cve@mitre.org\",\"tags\":[\"Patch\"]},{\"url\":\"https://github.com/shadow-maint/shadow/pull/687\",\"source\":\"cve@mitre.org\",\"tags\":[\"Issue Tracking\"]},{\"url\":\"https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/\",\"source\":\"cve@mitre.org\",\"tags\":[\"Exploit\",\"Third Party Advisory\"]},{\"url\":\"https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797\",\"source\":\"cve@mitre.org\",\"tags\":[\"Exploit\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\"]},{\"url\":\"https://github.com/shadow-maint/shadow/pull/687\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Issue Tracking\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2025/04/msg00026.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Exploit\",\"Third Party Advisory\"]},{\"url\":\"https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Exploit\",\"Third Party Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://github.com/shadow-maint/shadow/pull/687\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://lists.debian.org/debian-lts-announce/2025/04/msg00026.html\"}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2025-11-03T19:28:12.823Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2023-29383\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2025-02-06T21:21:27.050601Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-125\", \"description\": \"CWE-125 Out-of-bounds Read\"}]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2025-02-06T21:22:21.295Z\"}}], \"cna\": {\"affected\": [{\"vendor\": \"n/a\", \"product\": \"n/a\", \"versions\": [{\"status\": \"affected\", \"version\": \"n/a\"}]}], \"references\": [{\"url\": \"https://github.com/shadow-maint/shadow/pull/687\"}, {\"url\": \"https://github.com/shadow-maint/shadow/commit/e5905c4b84d4fb90aefcd96ee618411ebfac663d\"}, {\"url\": \"https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=31797\"}, {\"url\": \"https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/cve-2023-29383-abusing-linux-chfn-to-misrepresent-etc-passwd/\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"In Shadow 4.13, it is possible to inject control characters into fields provided to the SUID program chfn (change finger). Although it is not possible to exploit this directly (e.g., adding a new user fails because \\\\n is in the block list), it is possible to misrepresent the /etc/passwd file when viewed. Use of \\\\r manipulations and Unicode characters to work around blocking of the : character make it possible to give the impression that a new user has been added. In other words, an adversary may be able to convince a system administrator to take the system offline (an indirect, social-engineered denial of service) by demonstrating that \\\"cat /etc/passwd\\\" shows a rogue user account.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"text\", \"description\": \"n/a\"}]}], \"providerMetadata\": {\"orgId\": \"8254265b-2729-46b6-b9e3-3dfca2d5bfca\", \"shortName\": \"mitre\", \"dateUpdated\": \"2023-04-14T00:00:00.000Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2023-29383\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-11-03T19:28:12.823Z\", \"dateReserved\": \"2023-04-05T00:00:00.000Z\", \"assignerOrgId\": \"8254265b-2729-46b6-b9e3-3dfca2d5bfca\", \"datePublished\": \"2023-04-14T00:00:00.000Z\", \"assignerShortName\": \"mitre\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.