HOME VULNERABILITIESCVE-2018-18688

MEDIUM

CVE-2018-18688

CWE-347Published: January 7, 2021· Updated: Jun 17, 2026

5.3

CVSS v3.1

Official Description

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.

Technical Analysis

CVE-2018-18688 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityNone

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected Vendors & Products

Apple1 product(s)

macos

code-industry1 product(s)

master pdf editor

foxitsoftware2 product(s)

foxit readerphantompdf

gonitro2 product(s)

nitro pronitro reader

iskysoft2 product(s)

pdf editor 6pdfelement6

libreoffice1 product(s)

libreoffice

Linux1 product(s)

linux kernel

Microsoft1 product(s)

windows

nuance1 product(s)

power pdf standard

qoppa2 product(s)

pdf studiopdf studio viewer 2018

soft-xpansion2 product(s)

perfect pdf 10perfect pdf reader

Source: NVD CPE · 32 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://pdf-insecurity.org/signature/evaluation_2018.html

ADVISORYhttps://pdf-insecurity.org/signature/signature.html

ADVISORYhttps://www.foxitsoftware.com/support/security-bulletins.php

ADVISORYhttps://www.pdfa.org/recently-identified-pdf-digital-signature-vulnerabilities/

ADVISORYhttps://pdf-insecurity.org/signature/evaluation_2018.html

ADVISORYhttps://pdf-insecurity.org/signature/signature.html

ADVISORYhttps://www.foxitsoftware.com/support/security-bulletins.php

ADVISORYhttps://www.pdfa.org/recently-identified-pdf-digital-signature-vulnerabilities/

All References (8)

→

https://pdf-insecurity.org/signature/evaluation_2018.htmlThird Party Advisory

→

https://pdf-insecurity.org/signature/signature.htmlThird Party Advisory

→

https://www.foxitsoftware.com/support/security-bulletins.phpVendor Advisory

→

https://www.pdfa.org/recently-identified-pdf-digital-signature-vulnerabilities/Third Party Advisory

→

https://pdf-insecurity.org/signature/evaluation_2018.htmlThird Party Advisory

→

https://pdf-insecurity.org/signature/signature.htmlThird Party Advisory

→

https://www.foxitsoftware.com/support/security-bulletins.phpVendor Advisory

→

https://www.pdfa.org/recently-identified-pdf-digital-signature-vulnerabilities/Third Party Advisory

Quick Facts

CVE IDCVE-2018-18688

CVSS Score5.3 / 10

SeverityMEDIUM

WeaknessCWE-347

CISA KEVNo

Affected11 vendor(s)

PublishedJan 7, 2021

Related CVEs (CWE-347)

CVE-2019-1010263

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2018-18688 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.

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