CVE-2023-29409 (GCVE-0-2023-29409)

Vulnerability from cvelistv5 – Published: 2023-08-02 19:47 – Updated: 2025-02-13 16:49
VLAI
Title
Large RSA keys can cause high CPU usage in crypto/tls
Summary
Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.
Severity
No CVSS data available.
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-10-22 14:15 UTC
CWE
  • CWE-400 - Uncontrolled Resource Consumption
Assigner
References
Impacted products
Vendor Product Version CPE status
Go standard library crypto/tls Affected: 0 , < 1.19.12 (semver)
Affected: 1.20.0-0 , < 1.20.7 (semver)
Affected: 1.21.0-0 , < 1.21.0-rc.4 (semver)
guessed Create a notification for this product.
Credits
Mateusz Poliwczak
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-02T14:07:46.160Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://go.dev/issue/61460"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://go.dev/cl/515257"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI/m/Efv5DbZ9AwAJ"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://pkg.go.dev/vuln/GO-2023-1987"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20230831-0010/"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://security.gentoo.org/glsa/202311-09"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2023-29409",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-10-22T14:15:51.334084Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-10-22T14:16:01.839Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "crypto/tls",
          "product": "crypto/tls",
          "programRoutines": [
            {
              "name": "Conn.verifyServerCertificate"
            },
            {
              "name": "Conn.processCertsFromClient"
            },
            {
              "name": "Conn.Handshake"
            },
            {
              "name": "Conn.HandshakeContext"
            },
            {
              "name": "Conn.Read"
            },
            {
              "name": "Conn.Write"
            },
            {
              "name": "Dial"
            },
            {
              "name": "DialWithDialer"
            },
            {
              "name": "Dialer.Dial"
            },
            {
              "name": "Dialer.DialContext"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.19.12",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.20.7",
              "status": "affected",
              "version": "1.20.0-0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.21.0-rc.4",
              "status": "affected",
              "version": "1.21.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Mateusz Poliwczak"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to \u003c= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-11-25T11:09:25.696Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/issue/61460"
        },
        {
          "url": "https://go.dev/cl/515257"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI/m/Efv5DbZ9AwAJ"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2023-1987"
        },
        {
          "url": "https://security.netapp.com/advisory/ntap-20230831-0010/"
        },
        {
          "url": "https://security.gentoo.org/glsa/202311-09"
        }
      ],
      "title": "Large RSA keys can cause high CPU usage in crypto/tls"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2023-29409",
    "datePublished": "2023-08-02T19:47:23.829Z",
    "dateReserved": "2023-04-05T19:36:35.043Z",
    "dateUpdated": "2025-02-13T16:49:16.368Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2023-29409",
      "date": "2026-08-26",
      "epss": "0.01588",
      "percentile": "0.73788"
    },
    "microsoft_vex": {
      "current_release_date": "2026-02-18T02:56:34.000Z",
      "cve": "CVE-2023-29409",
      "id": "msrc_CVE-2023-29409",
      "initial_release_date": "2023-08-01T00:00:00.000Z",
      "product_status:fixed": "6",
      "product_status:known_affected": "6",
      "product_status:known_not_affected": "6",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "Large RSA keys can cause high CPU usage in crypto/tls",
      "url": "https://msrc.microsoft.com/csaf/vex/2023/msrc_cve-2023-29409.json",
      "version": "2"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2023-29409\",\"sourceIdentifier\":\"security@golang.org\",\"published\":\"2023-08-02T20:15:11.940\",\"lastModified\":\"2026-06-17T05:49:59.307\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to \u003c= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.\"}],\"affected\":[{\"source\":\"security@golang.org\",\"affectedData\":[{\"vendor\":\"Go standard library\",\"product\":\"crypto/tls\",\"defaultStatus\":\"unaffected\",\"collectionURL\":\"https://pkg.go.dev\",\"packageName\":\"crypto/tls\",\"programRoutines\":[{\"name\":\"Conn.verifyServerCertificate\"},{\"name\":\"Conn.processCertsFromClient\"},{\"name\":\"Conn.Handshake\"},{\"name\":\"Conn.HandshakeContext\"},{\"name\":\"Conn.Read\"},{\"name\":\"Conn.Write\"},{\"name\":\"Dial\"},{\"name\":\"DialWithDialer\"},{\"name\":\"Dialer.Dial\"},{\"name\":\"Dialer.DialContext\"}],\"versions\":[{\"version\":\"0\",\"lessThan\":\"1.19.12\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"1.20.0-0\",\"lessThan\":\"1.20.7\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"1.21.0-0\",\"lessThan\":\"1.21.0-rc.4\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L\",\"baseScore\":5.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":3.9,\"impactScore\":1.4}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2024-10-22T14:15:51.334084Z\",\"id\":\"CVE-2023-29409\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-400\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"1.19.12\",\"matchCriteriaId\":\"6A0D798F-972E-4789-9E60-F04864ACC5A0\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"1.20.0\",\"versionEndExcluding\":\"1.20.7\",\"matchCriteriaId\":\"98D9EFA9-C8A8-4C27-A1F2-DE9798D725FC\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:1.21.0:rc1:*:*:*:*:*:*\",\"matchCriteriaId\":\"64DE500E-0A99-4890-9D6E-0FBA9E9C3E0A\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:1.21.0:rc2:*:*:*:*:*:*\",\"matchCriteriaId\":\"EA9BD1EF-0172-4779-80DC-E316F5361D27\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:1.21.0:rc3:*:*:*:*:*:*\",\"matchCriteriaId\":\"80DFE31C-60CD-46E2-B86A-2C8E9057AFEA\"}]}]}],\"references\":[{\"url\":\"https://go.dev/cl/515257\",\"source\":\"security@golang.org\",\"tags\":[\"Patch\"]},{\"url\":\"https://go.dev/issue/61460\",\"source\":\"security@golang.org\",\"tags\":[\"Issue Tracking\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI/m/Efv5DbZ9AwAJ\",\"source\":\"security@golang.org\",\"tags\":[\"Mailing List\",\"Vendor Advisory\"]},{\"url\":\"https://pkg.go.dev/vuln/GO-2023-1987\",\"source\":\"security@golang.org\",\"tags\":[\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://security.gentoo.org/glsa/202311-09\",\"source\":\"security@golang.org\"},{\"url\":\"https://security.netapp.com/advisory/ntap-20230831-0010/\",\"source\":\"security@golang.org\"},{\"url\":\"https://go.dev/cl/515257\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\"]},{\"url\":\"https://go.dev/issue/61460\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Issue Tracking\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI/m/Efv5DbZ9AwAJ\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Vendor Advisory\"]},{\"url\":\"https://pkg.go.dev/vuln/GO-2023-1987\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://security.gentoo.org/glsa/202311-09\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"},{\"url\":\"https://security.netapp.com/advisory/ntap-20230831-0010/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-11T12:27:16+00:00",
      "cve": "CVE-2023-29409",
      "id": "CVE-2023-29409",
      "initial_release_date": "2023-08-02T00:00:00+00:00",
      "product_status:fixed": "936",
      "product_status:known_affected": "97",
      "product_status:known_not_affected": "1638",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "golang: crypto/tls: slow verification of certificate chains containing large RSA keys",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-29409.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://go.dev/issue/61460\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://go.dev/cl/515257\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI/m/Efv5DbZ9AwAJ\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://pkg.go.dev/vuln/GO-2023-1987\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://security.netapp.com/advisory/ntap-20230831-0010/\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://security.gentoo.org/glsa/202311-09\", \"tags\": [\"x_transferred\"]}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2024-08-02T14:07:46.160Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2023-29409\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2024-10-22T14:15:51.334084Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2024-10-22T14:15:57.131Z\"}}], \"cna\": {\"title\": \"Large RSA keys can cause high CPU usage in crypto/tls\", \"credits\": [{\"lang\": \"en\", \"value\": \"Mateusz Poliwczak\"}], \"affected\": [{\"vendor\": \"Go standard library\", \"product\": \"crypto/tls\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"1.19.12\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"1.20.0-0\", \"lessThan\": \"1.20.7\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"1.21.0-0\", \"lessThan\": \"1.21.0-rc.4\", \"versionType\": \"semver\"}], \"packageName\": \"crypto/tls\", \"collectionURL\": \"https://pkg.go.dev\", \"defaultStatus\": \"unaffected\", \"programRoutines\": [{\"name\": \"Conn.verifyServerCertificate\"}, {\"name\": \"Conn.processCertsFromClient\"}, {\"name\": \"Conn.Handshake\"}, {\"name\": \"Conn.HandshakeContext\"}, {\"name\": \"Conn.Read\"}, {\"name\": \"Conn.Write\"}, {\"name\": \"Dial\"}, {\"name\": \"DialWithDialer\"}, {\"name\": \"Dialer.Dial\"}, {\"name\": \"Dialer.DialContext\"}]}], \"references\": [{\"url\": \"https://go.dev/issue/61460\"}, {\"url\": \"https://go.dev/cl/515257\"}, {\"url\": \"https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI/m/Efv5DbZ9AwAJ\"}, {\"url\": \"https://pkg.go.dev/vuln/GO-2023-1987\"}, {\"url\": \"https://security.netapp.com/advisory/ntap-20230831-0010/\"}, {\"url\": \"https://security.gentoo.org/glsa/202311-09\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to \u003c= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"description\": \"CWE-400: Uncontrolled Resource Consumption\"}]}], \"providerMetadata\": {\"orgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"shortName\": \"Go\", \"dateUpdated\": \"2023-08-02T19:47:23.829Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2023-29409\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2024-10-22T14:16:01.839Z\", \"dateReserved\": \"2023-04-05T19:36:35.043Z\", \"assignerOrgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"datePublished\": \"2023-08-02T19:47:23.829Z\", \"assignerShortName\": \"Go\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.1"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.