Vulnerability-Lookup

GHSA-CPR2-5CHX-JMJ3

Vulnerability from github – Published: 2026-03-24 12:30 – Updated: 2026-03-24 12:30

Details

Base64 Decoder 1.1.2 contains a stack-based buffer overflow vulnerability that allows local attackers to execute arbitrary code by triggering a structured exception handler (SEH) overwrite. Attackers can craft a malicious input file that overflows a buffer, overwrites the SEH chain with a POP-POP-RET gadget address, and uses an egghunter payload to locate and execute shellcode for code execution.

Severity

8.4 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

8.6 (High)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2019-25634"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-787"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-24T12:16:04Z",
    "severity": "HIGH"
  },
  "details": "Base64 Decoder 1.1.2 contains a stack-based buffer overflow vulnerability that allows local attackers to execute arbitrary code by triggering a structured exception handler (SEH) overwrite. Attackers can craft a malicious input file that overflows a buffer, overwrites the SEH chain with a POP-POP-RET gadget address, and uses an egghunter payload to locate and execute shellcode for code execution.",
  "id": "GHSA-cpr2-5chx-jmj3",
  "modified": "2026-03-24T12:30:24Z",
  "published": "2026-03-24T12:30:24Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-25634"
    },
    {
      "type": "WEB",
      "url": "https://www.exploit-db.com/exploits/46625"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/base64-decoder-local-buffer-overflow-seh-egghunter"
    },
    {
      "type": "WEB",
      "url": "http://4mhz.de/b64dec.html"
    },
    {
      "type": "WEB",
      "url": "http://4mhz.de/download.php?file=b64dec-1-1-2.zip"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2019-25634 (GCVE-0-2019-25634)

Vulnerability from cvelistv5 – Published: 2026-03-24 11:27 – Updated: 2026-03-24 13:48

Title

Base64 Decoder 1.1.2 Local Buffer Overflow SEH Egghunter

Summary

Severity

8.6 (High)


                        
                          CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

8.4 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE

CWE-787 - Out-of-bounds Write

Assigner

VulnCheck

References

4 references

URL	Tags
https://www.exploit-db.com/exploits/46625	exploit
http://4mhz.de/b64dec.html	product
http://4mhz.de/download.php?file=b64dec-1-1-2.zip	product
https://www.vulncheck.com/advisories/base64-decod…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
4Mhz	Base64 Decoder	Affected: 1.1.2

Date Public

2019-03-28 00:00

Credits

Paolo Perego - paolo@armoredcode.com

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2019-25634",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-24T13:47:58.678069Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-24T13:48:49.934Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Base64 Decoder",
          "vendor": "4Mhz",
          "versions": [
            {
              "status": "affected",
              "version": "1.1.2"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Paolo Perego - paolo@armoredcode.com"
        }
      ],
      "datePublic": "2019-03-28T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Base64 Decoder 1.1.2 contains a stack-based buffer overflow vulnerability that allows local attackers to execute arbitrary code by triggering a structured exception handler (SEH) overwrite. Attackers can craft a malicious input file that overflows a buffer, overwrites the SEH chain with a POP-POP-RET gadget address, and uses an egghunter payload to locate and execute shellcode for code execution."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "LOCAL",
            "baseScore": 8.6,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 8.4,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "Out-of-bounds Write",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-24T11:27:07.919Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "ExploitDB-46625",
          "tags": [
            "exploit"
          ],
          "url": "https://www.exploit-db.com/exploits/46625"
        },
        {
          "name": "Official Product Homepage",
          "tags": [
            "product"
          ],
          "url": "http://4mhz.de/b64dec.html"
        },
        {
          "name": "Product Reference",
          "tags": [
            "product"
          ],
          "url": "http://4mhz.de/download.php?file=b64dec-1-1-2.zip"
        },
        {
          "name": "VulnCheck Advisory: Base64 Decoder 1.1.2 Local Buffer Overflow SEH Egghunter",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/base64-decoder-local-buffer-overflow-seh-egghunter"
        }
      ],
      "title": "Base64 Decoder 1.1.2 Local Buffer Overflow SEH Egghunter",
      "x_generator": {
        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2019-25634",
    "datePublished": "2026-03-24T11:27:07.919Z",
    "dateReserved": "2026-03-24T11:02:46.887Z",
    "dateUpdated": "2026-03-24T13:48:49.934Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Action not permitted

GHSA-CPR2-5CHX-JMJ3

CVE-2019-25634 (GCVE-0-2019-25634)

Tags

Sightings

Nomenclature