CVE-2025-15284
ADVISORY - githubSummary
Summary
The arrayLimit option in qs did not enforce limits for bracket notation (a[]=1&a[]=2), only for indexed notation (a[0]=1). This is a consistency bug; arrayLimit should apply uniformly across all array notations.
Note: The default parameterLimit of 1000 effectively mitigates the DoS scenario originally described. With default options, bracket notation cannot produce arrays larger than parameterLimit regardless of arrayLimit, because each a[]=value consumes one parameter slot. The severity has been reduced accordingly.
Details
The arrayLimit option only checked limits for indexed notation (a[0]=1&a[1]=2) but did not enforce it for bracket notation (a[]=1&a[]=2).
Vulnerable code (lib/parse.js:159-162):
if (root === '[]' && options.parseArrays) {
obj = utils.combine([], leaf); // No arrayLimit check
}
Working code (lib/parse.js:175):
else if (index <= options.arrayLimit) { // Limit checked here
obj = [];
obj[index] = leaf;
}
The bracket notation handler at line 159 uses utils.combine([], leaf) without validating against options.arrayLimit, while indexed notation at line 175 checks index <= options.arrayLimit before creating arrays.
PoC
const qs = require('qs');
const result = qs.parse('a[]=1&a[]=2&a[]=3&a[]=4&a[]=5&a[]=6', { arrayLimit: 5 });
console.log(result.a.length); // Output: 6 (should be max 5)
Note on parameterLimit interaction: The original advisory's "DoS demonstration" claimed a length of 10,000, but parameterLimit (default: 1000) caps parsing to 1,000 parameters. With default options, the actual output is 1,000, not 10,000.
Impact
Consistency bug in arrayLimit enforcement. With default parameterLimit, the practical DoS risk is negligible since parameterLimit already caps the total number of parsed parameters (and thus array elements from bracket notation). The risk increases only when parameterLimit is explicitly set to a very high value.
Common Weakness Enumeration (CWE)
Improper Input Validation
Improper Input Validation
Allocation of Resources Without Limits or Throttling
GitHub
3.9
CVSS SCORE
8.7high| Package | Type | OS Name | OS Version | Affected Ranges | Fix Versions |
|---|---|---|---|---|---|
| qs | npm | - | - | <6.14.1 | 6.14.1 |
CVSS:4 Severity and metrics
The CVSS metrics represent different qualitative aspects of a vulnerability that impact the overall score, as defined by the CVSS Specification.
The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone). One example of an Adjacent attack would be an ARP (IPv4) or neighbor discovery (IPv6) flood leading to a denial of service on the local LAN segment (e.g., CVE-2013-6014).
Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.
The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges.
There is no loss of confidentiality within the Vulnerable System.
There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
There is no loss of integrity within the Vulnerable System.
There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the Vulnerable System; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the Vulnerable System (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).
There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
NIST
2.2
CVSS SCORE
6.3mediumDebian
-
Ubuntu
-
CVSS SCORE
N/AmediumRed Hat
3.9
CVSS SCORE
7.5highChainguard
CGA-2xmq-258f-hwr2
-
Chainguard
CGA-6632-58pc-99c4
-
Chainguard
CGA-7fqq-c8pf-827j
-
Chainguard
CGA-7jm5-3j3p-wjcg
-
Chainguard
CGA-84gv-mffc-jrh2
-
Chainguard
CGA-fcrx-j379-xg2v
-
Chainguard
CGA-gpxj-r2m3-m6cm
-
Chainguard
CGA-jpmh-7ghg-8cr2
-
Chainguard
CGA-jwv9-77c2-p7p4
-
Chainguard
CGA-p4p8-689c-v8m4
-
Chainguard
CGA-qwmq-8x24-7gc7
-
Chainguard
CGA-vfq4-hhrf-934c
-
Chainguard
CGA-vjw5-pv6m-87q9
-
Chainguard
CGA-w9pp-j643-w8jj
-
Chainguard
CGA-wqvf-5f2q-jr8h
-
Chainguard
CGA-x345-fh92-pxw2
-
minimos
MINI-4p8v-g6w4-63hj
-
minimos
MINI-53mj-xjgj-7c68
-
minimos
MINI-5m3r-m39q-v7jg
-
minimos
MINI-65p2-m2xq-gjv2
-
minimos
MINI-9cwv-g765-fcw6
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minimos
MINI-9g82-6ghp-7pc5
-
minimos
MINI-c9gj-h97c-9hqm
-
minimos
MINI-gqwv-8r9g-8w5c
-
minimos
MINI-hx84-p2g2-85h6
-
minimos
MINI-m8vr-h9h6-wj2x
-
minimos
MINI-mx53-6gx4-hxmj
-
minimos
MINI-qgj5-jhr3-pg47
-
minimos
MINI-v26j-4xp8-852f
-