CVE-2020-24240

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2020-24240
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-24240.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2020-24240
Downstream
Published
2020-08-25T14:15:16Z
Modified
2026-07-08T17:56:40Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

GNU Bison before 3.7.1 has a use-after-free in _obstack_free in lib/obstack.c (called from gram_lex) when a '\0' byte is encountered. NOTE: there is a risk only if Bison is used with untrusted input, and the observed bug happens to cause unsafe behavior with a specific compiler/architecture. The bug report was intended to show that a crash may occur in Bison itself, not that a crash may occur in code that is generated by Bison.

References

Affected packages

Git / github.com/akimd/bison

Affected ranges

Type
GIT
Repo
https://github.com/akimd/bison
Events
Introduced
6675d36e2531f2573dcb8944bd9877214677e151
Last Affected
6675d36e2531f2573dcb8944bd9877214677e151
Fixed
be95a4fe2951374676efc9454ffee8638faaf68d
Database specific
Show details 
{
    "cpe":  "cpe:2.3:a:gnu:bison:3.7:*:*:*:*:*:*:*",
    "extracted_events":  [
        {
            "introduced":  "3.7"
        },
        {
            "last_affected":  "3.7"
        }
    ],
    "source":  [
        "CPE_STRING",
        "REFERENCES"
    ]
}

Affected versions

3.*
3.7
v3.*
v3.7

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-24240.json"
vanir_signatures 
[
    {
        "deprecated":  false,
        "digest":  {
            "line_hashes":  [
                "152892177091449443900596977177214106375",
                "110470093975942762776580447940415453127",
                "8556976720912662219078527567889747895"
            ],
            "threshold":  0.9
        },
        "id":  "CVE-2020-24240-85d57cd5",
        "signature_type":  "Line",
        "signature_version":  "v1",
        "source":  "https://github.com/akimd/bison/commit/be95a4fe2951374676efc9454ffee8638faaf68d",
        "target":  {
            "file":  "src/flex-scanner.h"
        }
    }
]
vanir_signatures_modified 
"2026-07-08T17:56:40Z"