Описание
Summary
The arrayLimit option in qs does not enforce limits for comma-separated values when comma: true is enabled, allowing attackers to cause denial-of-service via memory exhaustion. This is a bypass of the array limit enforcement, similar to the bracket notation bypass addressed in GHSA-6rw7-vpxm-498p (CVE-2025-15284).
Details
When the comma option is set to true (not the default, but configurable in applications), qs allows parsing comma-separated strings as arrays (e.g., ?param=a,b,c becomes ['a', 'b', 'c']). However, the limit check for arrayLimit (default: 20) and the optional throwOnLimitExceeded occur after the comma-handling logic in parseArrayValue, enabling a bypass. This permits creation of arbitrarily large arrays from a single parameter, leading to excessive memory allocation.
Vulnerable code (lib/parse.js: lines ~40-50):
The split(',') returns the array immediately, skipping the subsequent limit check. Downstream merging via utils.combine does not prevent allocation, even if it marks overflows for sparse arrays.This discrepancy allows attackers to send a single parameter with millions of commas (e.g., ?param=,,,,,,,,...), allocating massive arrays in memory without triggering limits. It bypasses the intent of arrayLimit, which is enforced correctly for indexed (a[0]=) and bracket (a[]=) notations (the latter fixed in v6.14.1 per GHSA-6rw7-vpxm-498p).
PoC
Test 1 - Basic bypass:
Configuration:
comma: truearrayLimit: 5throwOnLimitExceeded: trueExpected: Throws "Array limit exceeded" error. Actual: Parses successfully, creating an array of length 26.
Impact
Denial of Service (DoS) via memory exhaustion.
A denial of service flaw has been discovered in the qs npm package. When the comma option is set to true (not the default, but configurable in applications), qs allows parsing comma-separated strings as arrays (e.g., ?param=a,b,c becomes ['a', 'b', 'c']). However, the limit check for arrayLimit (default: 20) and the optional throwOnLimitExceeded occur after the comma-handling logic in parseArrayValue, enabling a bypass. This permits creation of arbitrarily large arrays from a single parameter, leading to excessive memory allocation.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Cryostat 4 | cryostat/cryostat-openshift-console-plugin-rhel9 | Fix deferred | ||
| Cryostat 4 | io.cryostat-cryostat | Fix deferred | ||
| Logging Subsystem for Red Hat OpenShift | openshift-logging/cluster-logging-operator-bundle | Fix deferred | ||
| Logging Subsystem for Red Hat OpenShift | openshift-logging/cluster-logging-rhel9-operator | Fix deferred | ||
| Logging Subsystem for Red Hat OpenShift | openshift-logging/elasticsearch6-rhel9 | Fix deferred | ||
| Logging Subsystem for Red Hat OpenShift | openshift-logging/elasticsearch-operator-bundle | Fix deferred | ||
| Logging Subsystem for Red Hat OpenShift | openshift-logging/elasticsearch-proxy-rhel9 | Fix deferred | ||
| Logging Subsystem for Red Hat OpenShift | openshift-logging/elasticsearch-rhel9-operator | Fix deferred | ||
| Logging Subsystem for Red Hat OpenShift | openshift-logging/eventrouter-rhel9 | Fix deferred | ||
| Logging Subsystem for Red Hat OpenShift | openshift-logging/fluentd-rhel9 | Fix deferred |
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Дополнительная информация
Статус:
EPSS
5.3 Medium
CVSS3
Связанные уязвимости
### Summary The `arrayLimit` option in qs does not enforce limits for comma-separated values when `comma: true` is enabled, allowing attackers to cause denial-of-service via memory exhaustion. This is a bypass of the array limit enforcement, similar to the bracket notation bypass addressed in GHSA-6rw7-vpxm-498p (CVE-2025-15284). ### Details When the `comma` option is set to `true` (not the default, but configurable in applications), qs allows parsing comma-separated strings as arrays (e.g., `?param=a,b,c` becomes `['a', 'b', 'c']`). However, the limit check for `arrayLimit` (default: 20) and the optional throwOnLimitExceeded occur after the comma-handling logic in `parseArrayValue`, enabling a bypass. This permits creation of arbitrarily large arrays from a single parameter, leading to excessive memory allocation. **Vulnerable code** (lib/parse.js: lines ~40-50): ```js if (val && typeof val === 'string' && options.comma && val.indexOf(',') > -1) { return val.split(','); } if (optio...
### Summary The `arrayLimit` option in qs does not enforce limits for comma-separated values when `comma: true` is enabled, allowing attackers to cause denial-of-service via memory exhaustion. This is a bypass of the array limit enforcement, similar to the bracket notation bypass addressed in GHSA-6rw7-vpxm-498p (CVE-2025-15284). ### Details When the `comma` option is set to `true` (not the default, but configurable in applications), qs allows parsing comma-separated strings as arrays (e.g., `?param=a,b,c` becomes `['a', 'b', 'c']`). However, the limit check for `arrayLimit` (default: 20) and the optional throwOnLimitExceeded occur after the comma-handling logic in `parseArrayValue`, enabling a bypass. This permits creation of arbitrarily large arrays from a single parameter, leading to excessive memory allocation. **Vulnerable code** (lib/parse.js: lines ~40-50): ```js if (val && typeof val === 'string' && options.comma && val.indexOf(',') > -1) { return val.split(','); } if
### Summary The `arrayLimit` option in qs does not enforce limits for ...
qs's arrayLimit bypass in comma parsing allows denial of service
EPSS
5.3 Medium
CVSS3