HighFix available

glibc — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2020-29573

sysdeps/i386/ldbl2mpn.c in the GNU C Library (aka glibc or libc6) before 2.23 on x86 targets has a stack-based buffer overflow if the input to any of the printf family of functions is an 80-bit long double with a non-canonical bit pattern, as seen when passing a \x00\x04\x00\x00\x00\x00\x00\x00\x00\x04 value to sprintf. NOTE: the issue does not affect glibc by default in 2016 or later (i.e., 2.23 or later) because of commits made in 2015 for inlining of C99 math functions through use of GCC built-ins. In other words, the reference to 2.23 is intentional despite the mention of "Fixed for glibc 2.33" in the 26649 reference.

Products: glibc
Affected versions: Not specified
Fixed versions: 2.23-1
CVEs: CVE-2020-29573
Confirmed fixed CVEs: Not specified
Updated in this feed: 1 Nov 2026, 13:52 UTC · Revision 1

Source evidence

DEBIAN-CVE-2020-29573

core-osv · Original source

Published 6 Dec 2020, 00:15 UTC

osv:DEBIAN-CVE-2020-29573

glibc

Fixed versions: 2.23-1

glibc

Fixed versions: 2.23-1

glibc

Fixed versions: 2.23-1

Complete source record

{
  "id": "a3ffba865a13b5784a973cd3c9b72029ec2db241a48ec1e7ae1f781dba811c45",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2020-29573",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2020-29573",
    "summary": "sysdeps/i386/ldbl2mpn.c in the GNU C Library (aka glibc or libc6) before 2.23 on x86 targets has a stack-based buffer overflow if the input to any of the printf family of functions is an 80-bit long double with a non-canonical bit pattern, as seen when passing a \\x00\\x04\\x00\\x00\\x00\\x00\\x00\\x00\\x00\\x04 value to sprintf. NOTE: the issue does not affect glibc by default in 2016 or later (i.e., 2.23 or later) because of commits made in 2015 for inlining of C99 math functions through use of GCC built-ins. In other words, the reference to 2.23 is intentional despite the mention of \"Fixed for glibc 2.33\" in the 26649 reference.",
    "evidence": "osv:DEBIAN-CVE-2020-29573",
    "products": [
      {
        "name": {
          "value": "glibc",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.23-1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "glibc",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.23-1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "glibc",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.23-1",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "DEBIAN-CVE-2020-29573",
      "aliases": [
        "DEBIAN-CVE-2020-29573"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.23-1"
                }
              ]
            }
          ],
          "package": {
            "name": "glibc",
            "purl": "pkg:deb/debian/glibc?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-29573.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.23-1"
                }
              ]
            }
          ],
          "package": {
            "name": "glibc",
            "purl": "pkg:deb/debian/glibc?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-29573.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.23-1"
                }
              ]
            }
          ],
          "package": {
            "name": "glibc",
            "purl": "pkg:deb/debian/glibc?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2020-29573.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-26T12:02:48.348237539Z",
      "provider": "osv",
      "upstream": [
        "CVE-2020-29573"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2020-29573"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2020-29573",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 452951,
  "published_at": "2020-12-06T00:15:11.567+00:00"
}