CVE-2018-18688

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.

Published: 2021-01-07 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-18688 is rated Low Risk (21.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-18688

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-17 0.15% 0.01% -0.15%
2 2023-08-14 0.12% 0.15% +0.04%
3 2023-03-07 — 0.12% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-18688

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N 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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2018-18688

Affected software / configurations for CVE-2018-18688

Vendor Product Version Raw CPE
code-industry master_pdf_editor 5.1.12 cpe:2.3:a:code-industry:master_pdf_editor:5.1.12:*:*:*:*:*:*:*
code-industry master_pdf_editor 5.1.68 cpe:2.3:a:code-industry:master_pdf_editor:5.1.68:*:*:*:*:*:*:*
foxitsoftware foxit_reader 9.4 cpe:2.3:a:foxitsoftware:foxit_reader:9.4:*:*:*:*:*:*:*
foxitsoftware phantompdf >= 9.0, < 9.4 cpe:2.3:a:foxitsoftware:phantompdf:*:*:*:*:*:*:*:*
foxitsoftware phantompdf 8.3.9 cpe:2.3:a:foxitsoftware:phantompdf:8.3.9:*:*:*:*:*:*:*
gonitro nitro_pro 11.0.3.173 cpe:2.3:a:gonitro:nitro_pro:11.0.3.173:*:*:*:*:*:*:*
gonitro nitro_reader 5.5.9.2 cpe:2.3:a:gonitro:nitro_reader:5.5.9.2:*:*:*:*:*:*:*
iskysoft pdf_editor_6 6.4.2.3521 cpe:2.3:a:iskysoft:pdf_editor_6:6.4.2.3521:*:*:*:professional:*:*:*
iskysoft pdfelement6 6.8.0.3523 cpe:2.3:a:iskysoft:pdfelement6:6.8.0.3523:*:*:*:professional:*:*:*
iskysoft pdfelement6 6.8.4.3921 cpe:2.3:a:iskysoft:pdfelement6:6.8.4.3921:*:*:*:professional:*:*:*
libreoffice libreoffice 6.0.6.2 cpe:2.3:a:libreoffice:libreoffice:6.0.6.2:*:*:*:*:*:*:*
libreoffice libreoffice 6.1.3.2 cpe:2.3:a:libreoffice:libreoffice:6.1.3.2:*:*:*:*:*:*:*
nuance power_pdf_standard 3.0.0.17 cpe:2.3:a:nuance:power_pdf_standard:3.0.0.17:*:*:*:*:*:*:*
nuance power_pdf_standard 3.0.0.30 cpe:2.3:a:nuance:power_pdf_standard:3.0.0.30:*:*:*:*:*:*:*
nuance power_pdf_standard 7.0 cpe:2.3:a:nuance:power_pdf_standard:7.0:*:*:*:*:*:*:*
qoppa pdf_studio 12.0.7 cpe:2.3:a:qoppa:pdf_studio:12.0.7:*:*:*:professional:*:*:*
qoppa pdf_studio_viewer_2018 2018.0.1 cpe:2.3:a:qoppa:pdf_studio_viewer_2018:2018.0.1:*:*:*:*:*:*:*
qoppa pdf_studio_viewer_2018 2018.2.0 cpe:2.3:a:qoppa:pdf_studio_viewer_2018:2018.2.0:*:*:*:*:*:*:*
soft-xpansion perfect_pdf_10 10.0.0.1 cpe:2.3:a:soft-xpansion:perfect_pdf_10:10.0.0.1:*:*:*:premium:*:*:*
soft-xpansion perfect_pdf_reader 13.0.3 cpe:2.3:a:soft-xpansion:perfect_pdf_reader:13.0.3:*:*:*:*:*:*:*
soft-xpansion perfect_pdf_reader 13.1.5 cpe:2.3:a:soft-xpansion:perfect_pdf_reader:13.1.5:*:*:*:*:*:*:*
foxitsoftware foxit_reader 9.1.0 cpe:2.3:a:foxitsoftware:foxit_reader:9.1.0:*:*:*:*:*:*:*
foxitsoftware foxit_reader 9.2.0 cpe:2.3:a:foxitsoftware:foxit_reader:9.2.0:*:*:*:*:*:*:*
code-industry master_pdf_editor 5.1.24 cpe:2.3:a:code-industry:master_pdf_editor:5.1.24:*:*:*:*:*:*:*
iskysoft pdf_editor_6 6.6.2.3315 cpe:2.3:a:iskysoft:pdf_editor_6:6.6.2.3315:*:*:*:professional:*:*:*
iskysoft pdf_editor_6 6.7.6.3399 cpe:2.3:a:iskysoft:pdf_editor_6:6.7.6.3399:*:*:*:professional:*:*:*
iskysoft pdfelement6 6.7.1.3355 cpe:2.3:a:iskysoft:pdfelement6:6.7.1.3355:*:*:*:professional:*:*:*
iskysoft pdfelement6 6.7.6.3399 cpe:2.3:a:iskysoft:pdfelement6:6.7.6.3399:*:*:*:professional:*:*:*
libreoffice libreoffice 6.1.0.3 cpe:2.3:a:libreoffice:libreoffice:6.1.0.3:*:*:*:*:*:*:*

References for CVE-2018-18688

cvelogic Threat Intelligence