Inefficient Regular Expression Complexity in marked

Description

Impact

What kind of vulnerability is it?

Denial of service.

The regular expression block.def may cause catastrophic backtracking against some strings.
PoC is the following.

import * as marked from "marked";

marked.parse(`[x]:${' '.repeat(1500)}x ${' '.repeat(1500)} x`);

Who is impacted?

Anyone who runs untrusted markdown through marked and does not use a worker with a time limit.

Patches

Has the problem been patched?

Yes

What versions should users upgrade to?

4.0.10

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

Do not run untrusted markdown through marked or run marked on a worker thread and set a reasonable time limit to prevent draining resources.

References

Are there any links users can visit to find out more?

  • https://marked.js.org/using_advanced#workers
  • https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS

For more information

If you have any questions or comments about this advisory:

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2022-01-14 21:04:41 UTC
Updated
2023-11-29 20:51:52 UTC
GitHub reviewed
2022-01-14 19:56:20 UTC
NVD published
2022-01-14

EPSS Score

Score Percentile
0.71% 72.19%

CVSS Scores

Base score Version Severity Vector
7.5 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

CWEs

CWE id Name
CWE-400 Uncontrolled Resource Consumption
CWE-1333 Inefficient Regular Expression Complexity

Credits

  • makenowjust (analyst)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
npm marked < 4.0.10 4.0.10

References

cvelogic Threat Intelligence