Security readout for executives and security teams
Plain-English summary
CVE-2020-25725 is a memory safety flaw in Xpdf 4.02. A specially crafted PDF involving Type 3 fonts could trigger a crash through use of freed memory. The business impact is mainly service or workstation disruption, not data theft, based on the supplied CVSS vector.
Executive priority
Treat as a routine but real availability risk. Patch through normal vulnerability management, with faster handling for desktops, servers, or automation that process external PDFs. There is no source-backed evidence here of active exploitation or data compromise.
Technical view
Xpdf 4.02 mishandles nested Type 3 characters when a character refers to another character in the same Type 3 font. In SplashOutputDev::endType3Char, t3GlyphStack->cache can be used after it is freed, causing a CWE-416 heap-use-after-free with high availability impact.
Likely exposure
Exposure is limited to environments running Xpdf 4.02, especially where users or workflows open PDFs from untrusted or external sources. The bundle does not identify other affected products.
Exploitation context
The supplied sources do not show CISA KEV listing or active exploitation. The CVSS vector indicates local attack vector, low complexity, low privileges, required user interaction, no confidentiality or integrity impact, and high availability impact.
Researcher notes
The key technical evidence is a heap-use-after-free in Xpdf 4.02 involving Type 3 font cache handling after an incomplete prior fix for nested Type 3 characters. Patch details and exact fixed upstream version are not provided in the bundle.
Mitigation direction
- Inventory systems and packages for Xpdf 4.02.
- Review Glyph & Cog, Red Hat, and Fedora guidance for available fixes.
- Update Xpdf or distro packages when vendor-supported fixes are available.
- Limit opening untrusted PDFs on affected systems until remediated.
- Prioritize hosts that process external PDFs regularly.
Validation and detection
- Confirm whether Xpdf 4.02 is installed or packaged in managed images.
- Check package advisory metadata for the Fedora or vendor-remediated build.
- Identify workflows that open customer, email, or internet-sourced PDFs.
- Review crash reports involving Xpdf PDF rendering or Type 3 fonts.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-416: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-25725 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H1.33.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://forum.xpdfreader.com/viewtopic.php?f=3&t=41915CVE reference · x_refsource_MISC
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-25725CVE reference · x_refsource_CONFIRM
- FEDORA-2021-4a437fe032CVE reference · vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-013d9a30e0CVE reference · vendor-advisory, x_refsource_FEDORA
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.