CVE-2021-23354: Regular Expression Denial of Service (ReDoS)
Vulnerability summary
CVE-2021-23354 is a high (CVSS 7.5) vulnerability in adaltas printf. EPSS estimates a 2.18% chance of exploitation in the next 30 days, higher than 82.3% of scored vulnerabilities. 1 public exploit is recorded.
Not severe (CVSS 5.3, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 12-03-2021PublishedVulnerability first disclosed.
- 17-09-2024Last modifiedVulnerability information updated.
Description
The package printf before 0.6.1 are vulnerable to Regular Expression Denial of Service (ReDoS) via the regex string /\%(?:\(([\w_.]+)\)|([1-9]\d*)\$)?([0 +\-\]*)(\*|\d+)?(\.)?(\*|\d+)?[hlL]?([\%bscdeEfFgGioOuxX])/g in lib/printf.js. The vulnerable regular expression has cubic worst-case time complexity.
CVSS metrics
4 scores · 3 sources · 2 versions- CVE.orgCNA5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LDiffers
- OSV · NpmEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
2.18%
Chance of exploitation in the next 30 days
Percentile
82%
Versus all other CVEs
30-day change
No change 0.00 pp
From 2.18% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundNode Printf
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Adaltas1 product
- printf< 0.6.1
Npm1 product
- printf< 0.6.1
2 vendors · 2 products
References
5 links- github.com/adaltas/node-printf/issues/31X Refsource MISCWEBExploitIssue TrackingThird Party Advisory
