Описание
NLTK before 3.10.3 contains a regular expression denial of service (ReDoS) vulnerability in the tgrep module. The _tgrep_node_action function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or timeout. An attacker who controls the tgrep pattern (e.g., via tgrep_positions() or tgrep_compile() exposed to external input) can supply a pattern that triggers catastrophic backtracking, causing indefinite CPU saturation that blocks the Python process.
A flaw was found in NLTK, specifically within its tgrep module. This vulnerability, known as Regular Expression Denial of Service (ReDoS), allows a remote attacker to provide specially crafted regular expressions. When processed, these expressions can cause indefinite CPU saturation, leading to a complete denial of service for the Python process utilizing the NLTK library.
Отчет
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in NLTK's tgrep module within the _tgrep_node_action function. When processing user-supplied regular expressions inside /regex/ pattern nodes via functions such as tgrep_positions() or tgrep_compile(), NLTK executes re.search without input validation or execution timeouts. If an application exposes these interfaces to unauthenticated or low-privileged attackers, supplying a specially crafted regular expression triggers catastrophic backtracking, resulting in CPU saturation and process-level denial of service.
Меры по смягчению последствий
Sanitize or restrict external input passed to NLTK's tgrep compilation functions to prevent execution of untrusted regular expressions, or enforce application-level timeouts using process isolation/multiprocessing wrappers to restrict CPU consumption.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Exploit Intelligence | exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 | Out of support scope | ||
| Lightspeed Core | lightspeed-core/lightspeed-stack-rhel9 | Fix deferred | ||
| Lightspeed Core | lightspeed-core/rag-tool-cpu-rhel9 | Fix deferred | ||
| Lightspeed Core | lightspeed-core/rag-tool-cuda-12.9-rhel9 | Fix deferred | ||
| OpenShift Lightspeed | openshift-lightspeed/lightspeed-ocp-rag-rhel9 | Fix deferred | ||
| OpenShift Lightspeed | openshift-lightspeed/lightspeed-service-api-rhel9 | Fix deferred | ||
| OpenShift Lightspeed | openshift-lightspeed-tech-preview/lightspeed-rag-tool-rhel9 | Fix deferred | ||
| Red Hat Ansible Automation Platform 2 | ansible-automation-platform-25/lightspeed-chatbot-rhel8 | Out of support scope | ||
| Red Hat OpenShift AI (RHOAI) | rhoai/odh-llama-stack-core-rhel9 | Fix deferred | ||
| Red Hat OpenShift AI (RHOAI) | rhoai/odh-ogx-core-rhel9 | Fix deferred |
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Дополнительная информация
Статус:
EPSS
5.9 Medium
CVSS3
Связанные уязвимости
NLTK before 3.10.3 contains a regular expression denial of service (ReDoS) vulnerability in the tgrep module. The _tgrep_node_action function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or timeout. An attacker who controls the tgrep pattern (e.g., via tgrep_positions() or tgrep_compile() exposed to external input) can supply a pattern that triggers catastrophic backtracking, causing indefinite CPU saturation that blocks the Python process.
NLTK before 3.10.3 contains a regular expression denial of service (ReDoS) vulnerability in the tgrep module. The _tgrep_node_action function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or timeout. An attacker who controls the tgrep pattern (e.g., via tgrep_positions() or tgrep_compile() exposed to external input) can supply a pattern that triggers catastrophic backtracking, causing indefinite CPU saturation that blocks the Python process.
NLTK before 3.10.3 contains a regular expression denial of service (Re ...
NLTK: ReDoS in nltk.tgrep via unvalidated user-supplied regular expressions
EPSS
5.9 Medium
CVSS3