CVE-2019-25777
YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.
A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options.
A perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- Puntuación base: 7.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.22%
- Percentil entre todas las CVEs puntuadas: 12
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access85 % - Impacto principal
T1059Command and Scripting Interpreterexecution90 % - Impacto secundario
T1068Exploitation for Privilege Escalationprivilege escalation70 %
Vector AV:N/PR:N/UI:N indica red sin autenticación (T1190). Descripción explícita de 'arbitrary code execution' y manipulación de variables de paquete para ejecutar código Perl arbitrary mediante desserialización de YAML malicioso.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-502, CWE-914
Referencias
JSON original (NVD)
Mostrar
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"id": "CVE-2019-25777",
"cveTags": [],
"metrics": {
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{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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"id": "CVE-2019-25777",
"role": "CISA Coordinator",
"options": [
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"exploitation": "none"
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{
"automatable": "yes"
},
{
"technicalImpact": "partial"
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"version": "2.0.3",
"timestamp": "2026-10-06T16:58:07.558999Z"
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"cvssMetricV31": [
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"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"integrityImpact": "LOW",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "LOW",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
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"impactScore": 3.4,
"exploitabilityScore": 3.9
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"affected": [
{
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"affectedData": [
{
"repo": "https://github.com/ingydotnet/yaml-pm",
"modules": [
"YAML"
],
"versions": [
{
"status": "affected",
"version": "0",
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"packageURL": "pkg:cpan/YAML",
"packageName": "YAML",
"programFiles": [
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],
"collectionURL": "https://cpan.org/modules",
"defaultStatus": "unaffected",
"programRoutines": [
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"published": "2026-10-05T07:16:29.557",
"references": [
{
"url": "https://github.com/ingydotnet/yaml-pm/commit/bace96b5e6661d521c7c515c94a09e081c911fce.patch",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
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"url": "https://metacpan.org/release/TINITA/YAML-1.28/changes",
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"url": "http://www.openwall.com/lists/oss-security/2026/10/05/7",
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],
"descriptions": [
{
"lang": "en",
"value": "YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.\n\nA perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts the name, so the target can be @INC or YAML's own load options.\n\nA perl/glob document that sets $YAML::LoadCode or $YAML::UseCode turns on code loading, which is off by default, for every later Load() in the process. A perl/code document is then passed to a string eval, so an attacker who supplies two documents to separate Load() calls in one process can execute arbitrary Perl code."
}
],
"lastModified": "2026-10-06T17:17:09.893",
"sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
}