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Fencer Vulns
high 8.8

CVE-2020-13580 in the critical feed json

An exploitable heap-based buffer overflow vulnerability exists in the PlanMaker document parsing functionality of SoftMaker Office 2021’s P…

published 2021-02-04 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-5827

cvss
8.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
70.7%
EPSS 70.7% chance of exploitation in 30 days, percentile 99.3%
public exploits
0
none known

Summary

An exploitable heap-based buffer overflow vulnerability exists in the PlanMaker document parsing functionality of SoftMaker Office 2021’s PlanMaker application. A specially crafted document can cause the document parser to explicitly trust a length from a particular record type and use it to write a 16-bit null relative to a buffer allocated on the stack. Due to a lack of bounds-checking on this value, this can allow an attacker to write to memory outside of the buffer and controllably corrupt memory. This can allow an attacker to earn code execution under the context of the application. An attacker can entice the victim to open a document to trigger this vulnerability.

Exploit prediction

70.69% chance of exploitation in the next 30 days, higher than 99.3% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2020-1191 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 Softmaker Software

Classification

Weakness

References

Sources

Fencer Vulns 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.