7.8

CVE-2021-34121: htmldoc_project htmldoc Out-of-bounds Read

CVSS: 7.8v3.1HighModified
AliasesUBUNTU-CVE-2021-34121DEBIAN-CVE-2021-34121
Published 18-07-2023Last modified 28-10-2024
Open JSON

Vulnerability summary

CVE-2021-34121 is a high (CVSS 7.8) Out-of-bounds Read vulnerability in htmldoc_project htmldoc. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 25.7% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
41/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (NVD)
EPSS score
0.34%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
USN-7189-1

Timeline

  1. 18-07-2023
    PublishedVulnerability first disclosed.
  2. 28-10-2024
    Last modifiedVulnerability information updated.

Description

An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

26%

Versus all other CVEs

30-day change

0.00 pp

From 0.34% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.34%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Htmldoc

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • htmldoc< 1.9.13-1
Htmldoc_project1 product
Ubuntu1 product
  • htmldoc< 1.8.27-8ubuntu1+esm3 | < 1.8.27-8ubuntu1.1+esm2 | < 1.9.2-1ubuntu0.2+esm1 | < 1.9.7-1ubuntu0.3+esm1

3 vendors · 3 products

References

6 links