Alertas de Seguridad de la Información

NLTK (Natural Language Toolkit) anterior a versión 3.9.3 no valida la integridad de paquetes descargados antes de su extracción, permitiendo ataques de intermediario (MITM) o envenenamiento DNS para inyectar contenido malicioso. Afecta principalmente a empresas en LATAM que usan este framework en pipelines de procesamiento de lenguaje natural, análisis de datos y sistemas de chatbots.

NLTK anterior a la versión 3.10.0 contiene una vulnerabilidad que permite la lectura arbitraria de archivos locales mediante StreamBackedCorpusView, eludiendo los controles de pathsec.ENFORCE al llamar directamente a builtins.open(). Un atacante que controle el parámetro fileid puede acceder a archivos sensibles del sistema, credenciales de aplicaciones y datos confidenciales, independientemente de la configuración de seguridad habilitada. Afecta principalmente a aplicaciones de procesamiento de lenguaje natural desplegadas en entornos empresariales de LATAM.

NLTK versiones anteriores a 3.9.4 contienen una vulnerabilidad de recursión no acotada en JSONTaggedDecoder.decode_obj() que permite a atacantes causar denegación de servicio mediante estructuras JSON profundamente anidadas. Un payload malicioso que exceda el límite de recursión desencadena una excepción RecursionError no controlada que causa el fallo del proceso Python. Afecta aplicaciones de procesamiento de lenguaje natural en infraestructuras LATAM, incluyendo sistemas de análisis de datos y chatbots empresariales.

NLTK versions before 3.10.2 contain a symlink-based sandbox bypass in FramenetCorpusReader that allows attackers to read arbitrary XML files outside the corpus root. Attackers can place symlinks with names containing no path separators inside the corpus subdirectory, which pass the path validation guard and are resolved to files outside the intended corpus root when accessed via frame_by_name(), _…

NLTK versions before 3.10.0 default to ENFORCE=False in pathsec.py, causing all security validation functions to emit warnings instead of raising exceptions. Attackers can bypass path traversal and pickle deserialization protections by exploiting the disabled security controls that are only active when manually enabled.

NLTK before 3.10.3 contains a remote code execution vulnerability in AllowlistUnpickler that validates only the pickle module string and not the global name, allowing attackers to resolve dotted names by attribute traversal to callables outside the allowlisted namespace. Attackers can craft untrusted transition-parser models that execute arbitrary commands when TransitionParser.parse loads the mod…

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORD_RE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix [a-z0-9]+(?:[.\-][a-z0-9]+)* is unbounded. Input consisting of many alternating label separators can be partitioned in exponentially many ways, and because the branch also requires a trailing top-level domain t…

NLTK (Natural Language Toolkit) before version 3.9.3 contains an eval injection vulnerability in the nltk.collocations module that allows an attacker who controls command-line arguments to execute arbitrary Python code. When collocations.py is invoked directly, the __main__ block passes command-line arguments directly to eval() as suffixes of BigramAssocMeasures without allowlist validation or san…

In nltk/nltk versions 3.9.3 and earlier, five Stanford interface classes (StanfordPOSTagger, StanfordNERTagger, StanfordParser, StanfordDependencyParser, and StanfordNeuralDependencyParser) are vulnerable to untrusted JAR code execution. These classes accept user-controllable JAR paths and execute them via the `java()` function, which invokes `subprocess.Popen()` without integrity verification. Th…

NLTK version 3.9.4 is vulnerable to a path traversal attack due to an incomplete fix for GitHub Issue #3504. The `_UNSAFE_NO_PROTOCOL_RE` regex in `nltk/data.py` checks for literal `../` sequences but fails to account for percent-encoded traversal sequences such as `..%2f`. The `url2pathname()` function decodes these sequences after the validation step, allowing an attacker to bypass the protectio…

NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. Prior to 3.10.0-rc1, nltk.data.load() in NLTK is vulnerable to path traversal via URL-encoded path separators and traversal segments when using the nltk: URL scheme. The unsafe-path regex check is performed before url2pathname() deco…

A vulnerability in `nltk.app.wordnet_app` up to version 3.9.3 allows unauthenticated remote shutdown of the local WordNet Browser HTTP server when started in its default mode. The server listens on all interfaces and processes a specific unauthenticated GET request (`/SHUTDOWN%20THE%20SERVER`) to terminate the process immediately via `os._exit(0)`. This results in a denial of service, impacting se…