CVE-2023-42821: github.com/gomarkdown/markdown Out-of-bounds Read while parsing citations
Vulnerability summary
CVE-2023-42821 is a high (CVSS 7.5) Out-of-bounds Read vulnerability in gomarkdown markdown. EPSS estimates a 1.25% chance of exploitation in the next 30 days, higher than 69.4% of scored vulnerabilities. 1 public exploit is recorded.
Public exploit (GitHub, Date unknown)
Source freshness unavailable
How is this decided?Timeline
- 22-09-2023PublishedVulnerability first disclosed.
- 24-09-2024Last modifiedVulnerability information updated.
Description
The package `github.com/gomarkdown/markdown` is a Go library for parsing Markdown text and rendering as HTML. Prior to pseudoversion `0.0.0-20230922105210-14b16010c2ee`, which corresponds with commit `14b16010c2ee7ff33a940a541d993bd043a88940`, parsing malformed markdown input with parser that uses parser.Mmark extension could result in out-of-bounds read vulnerability. To exploit the vulnerability, parser needs to have `parser.Mmark` extension set. The panic occurs inside the `citation.go` file on the line 69 when the parser tries to access the element past its length. This can result in a denial of service. Commit `14b16010c2ee7ff33a940a541d993bd043a88940`/pseudoversion `0.0.0-20230922105210-14b16010c2ee` contains a patch for this issue.
CVSS metrics
5 scores · 5 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · GoEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
1.25%
Chance of exploitation in the next 30 days
Percentile
69%
Versus all other CVEs
30-day change
No change 0.00 pp
From 1.25% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundMarkdown
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian1 product
- golang-github-gomarkdown-markdownAll versions (No fix recorded) | < 0.0~git20231115.a660076-1
Github.com/gomarkdown1 product
- markdown< 0.0.0-20230922105210-14b16010c2ee
Gomarkdown1 product
- markdown< 0.0.0-20230922105210-14b16010c2ee | na
Ubuntu1 product
- golang-github-gomarkdown-markdownAll versions (No fix recorded)
4 vendors · 4 products
References
8 links- github.com/gomarkdown/markdown/security/advisories/GHSA-m9xq-6h2j-65r2X Refsource CONFIRMREPORTWEBAdvisoryExploitVendor Advisory
- github.com/gomarkdown/markdown/commit/14b16010c2ee7ff33a940a541d993bd043a88940X Refsource MISCREPORTWEBFIXPatch
- github.com/gomarkdown/markdown/blob/7478c230c7cd3e7328803d89abe591d0b61c41e4/parser/citation.goX Refsource MISCREPORTWEBProduct
