CVE-2021-43523

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Source
https://cve.org/CVERecord?id=CVE-2021-43523
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-43523.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2021-43523
Downstream
Published
2021-11-10T15:15:12.213Z
Modified
2026-07-09T00:37:45.744507Z
Severity
  • 9.6 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

In uClibc and uClibc-ng before 1.0.39, incorrect handling of special characters in domain names returned by DNS servers via gethostbyname, getaddrinfo, gethostbyaddr, and getnameinfo can lead to output of wrong hostnames (leading to domain hijacking) or injection into applications (leading to remote code execution, XSS, applications crashes, etc.). In other words, a validation step, which is expected in any stub resolver, does not occur.

Database specific 
{
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "last_affected": "0.9.33.2"
                }
            ],
            "cpes": [
                "cpe:2.3:a:uclibc:uclibc:*:*:*:*:*:*:*:*"
            ],
            "source": "CPE_RANGE",
            "vendor_product": "uclibc:uclibc"
        }
    ]
}
References

Affected packages

Git / github.com/wbx-github/uclibc-ng

Affected ranges

Type
GIT
Repo
https://github.com/wbx-github/uclibc-ng
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
98680eec548b921abecc641b70246587ffbbdc0a
Fixed
0f822af0445e5348ce7b7bd8ce1204244f31d174
Database specific 
{
    "cpe": "cpe:2.3:a:uclibc-ng_project:uclibc-ng:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "1.0.39"
        }
    ],
    "source": [
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

v1.*
v1.0.0
v1.0.1
v1.0.10
v1.0.11
v1.0.12
v1.0.13
v1.0.14
v1.0.15
v1.0.16
v1.0.17
v1.0.18
v1.0.19
v1.0.2
v1.0.20
v1.0.21
v1.0.22
v1.0.23
v1.0.24
v1.0.25
v1.0.26
v1.0.27
v1.0.28
v1.0.29
v1.0.30
v1.0.31
v1.0.32
v1.0.33
v1.0.34
v1.0.35
v1.0.36
v1.0.37
v1.0.38
v1.0.4
v1.0.5
v1.0.6
v1.0.7
v1.0.8
v1.0.9

Database specific

vanir_signatures_modified 
"2026-07-09T00:37:45Z"
vanir_signatures 
[
    {
        "signature_type": "Line",
        "deprecated": false,
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "149264702995849926995880357077148658418",
                "243810231544876742984716147609756610546",
                "187030675381736448097324690676783753625",
                "100290982701279520762322895167055908560",
                "254510051435418387231807586264706432803",
                "127470599868015528932188807542183778315",
                "238947607400550915323449413440525444659",
                "100291630674831964903902157310892998",
                "151454825748915532144619970068739494951",
                "89856833502807635002347470409707494480",
                "148312366988786653925409142798107704914",
                "339618317688292319097571634859286458989",
                "33363081068604607857297487112370033761",
                "279277696107889254542476767238182568323",
                "8014272486930206910113337858133153610",
                "67404679295335727849053402728486910846",
                "39664672908463604438436562535780125086",
                "74344633561521975023763775821125317541",
                "221091041025799427006518368187122880931",
                "307121273801650420540320388845313791754",
                "125598997618452317981920348047648707664",
                "21760855911259382741492069268857317211",
                "293885711760885308786630919328611396419",
                "215376830079803944236967906711375132863",
                "280789395264276232750830863600257661405",
                "178219953907381805852041282970328377271",
                "242032130722139442784584669633065954461",
                "149298575035780289452995437699480611392",
                "133481329120677515855056248096345088620",
                "167874028530862599751312015329974450094",
                "193298813581817783774239728871110003957",
                "311424175083350137278754627965055219714",
                "207071184630088015915361978077643763745",
                "35112011265620622621068167055770592639",
                "74456878702499903498546084175784394791",
                "32208519443934144979955140749924375756",
                "258172524578157566106918639407807282432",
                "257697376243251966081591258945331191205",
                "148840428707586260763930967901346675651"
            ]
        },
        "signature_version": "v1",
        "source": "https://github.com/wbx-github/uclibc-ng/commit/0f822af0445e5348ce7b7bd8ce1204244f31d174",
        "id": "CVE-2021-43523-13627d42",
        "target": {
            "file": "libc/inet/resolv.c"
        }
    },
    {
        "signature_type": "Function",
        "deprecated": false,
        "digest": {
            "length": 2922.0,
            "function_hash": "142910486240576585748756844269932716179"
        },
        "signature_version": "v1",
        "source": "https://github.com/wbx-github/uclibc-ng/commit/0f822af0445e5348ce7b7bd8ce1204244f31d174",
        "id": "CVE-2021-43523-95c3f977",
        "target": {
            "function": "gethostbyaddr_r",
            "file": "libc/inet/resolv.c"
        }
    },
    {
        "signature_type": "Function",
        "deprecated": false,
        "digest": {
            "length": 6923.0,
            "function_hash": "162191713996631590485357856097300099751"
        },
        "signature_version": "v1",
        "source": "https://github.com/wbx-github/uclibc-ng/commit/0f822af0445e5348ce7b7bd8ce1204244f31d174",
        "id": "CVE-2021-43523-e3aa6a0d",
        "target": {
            "function": "__dns_lookup",
            "file": "libc/inet/resolv.c"
        }
    }
]
source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-43523.json"