CVE-2018-18688

moderate-risk
Published 2021-01-07

The Portable Document Format (PDF) specification does not provide any information regarding the concrete procedure of how to validate signatures. Consequently, an Incremental Saving vulnerability exists in multiple products. When an attacker uses the Incremental Saving feature to add pages or annotations, Body Updates are displayed to the user without any action by the signature-validation logic. This affects Foxit Reader before 9.4 and PhantomPDF before 8.3.9 and 9.x before 9.4. It also affects LibreOffice, Master PDF Editor, Nitro Pro, Nitro Reader, Nuance Power PDF Standard, PDF Editor 6 Pro, PDFelement6 Pro, PDF Studio Viewer 2018, PDF Studio Pro, Perfect PDF 10 Premium, and Perfect PDF Reader.

Do I need to act?

-
0.00% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.3/10 Medium
NETWORK / LOW complexity

Affected Products (20)

Master Pdf Editor
Master Pdf Editor
Nitro Reader
Pdf Editor 6
Pdfelement6
Pdfelement6
Power Pdf Standard
Power Pdf Standard
Power Pdf Standard
Pdf Studio
Pdf Studio Viewer 2018
Pdf Studio Viewer 2018
Perfect Pdf 10
Perfect Pdf Reader

Affected Vendors

Foxitsoftware Libreoffice Nuance Gonitro Iskysoft Code-Industry Qoppa Soft-Xpansion

References (8)

Third Party Advisory https://pdf-insecurity.org/signature/evaluation_2018.html
Third Party Advisory https://pdf-insecurity.org/signature/signature.html
Vendor Advisory https://www.foxitsoftware.com/support/security-bulletins.php
Third Party Advisory https://www.pdfa.org/recently-identified-pdf-digital-signature-vulnerabilities/
Third Party Advisory https://pdf-insecurity.org/signature/evaluation_2018.html
Third Party Advisory https://pdf-insecurity.org/signature/signature.html
Vendor Advisory https://www.foxitsoftware.com/support/security-bulletins.php
Third Party Advisory https://www.pdfa.org/recently-identified-pdf-digital-signature-vulnerabilities/
43
/ 100
moderate-risk
Severity 21/34 · High
Exploitability 0/34 · Minimal
Exposure 22/34 · High