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Fencer Intel
high 8.8

CVE-2021-21797 in the critical feed json

An exploitable double-free vulnerability exists in the JavaScript implementation of Nitro Pro PDF.

published 5y ago modified 4mo ago also EUVD-2021-8969

cvss
8.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
15.0%
EPSS 15.0% chance of exploitation in 30 days, percentile 96%
public exploits
0
none known

Summary

An exploitable double-free vulnerability exists in the JavaScript implementation of Nitro Pro PDF. A specially crafted document can cause a reference to a timeout object to be stored in two different places. When closed, the document will result in the reference being released twice. This can lead to code execution under the context of the application. An attacker can convince a user to open a document to trigger this vulnerability.

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Exploit prediction

15.05% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2021-1266 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 8.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • n/a Nitro Pro

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.