This affects the package juce-framework/JUCE before 6.1.5. This vulnerability is triggered when a malicious archive is crafted with an entry containing a symbolic link. When extracted, the symbolic link is followed outside of the target dir allowing writing arbitrary files on the target host. In some cases, this can allow an attacker to execute arbitrary code. The vulnerable code is in the ZipFile::uncompressEntry function in juce_ZipFile.cpp and is executed when the archive is extracted upon calling uncompressTo() on a ZipFile object.
[
    {
        "source": "https://github.com/juce-framework/juce/commit/2e874e80cba0152201aff6a4d0dc407997d10a7f",
        "signature_version": "v1",
        "deprecated": false,
        "id": "CVE-2021-23521-070bd10a",
        "target": {
            "function": "ZipFile::uncompressEntry",
            "file": "modules/juce_core/zip/juce_ZipFile.cpp"
        },
        "signature_type": "Function",
        "digest": {
            "length": 1638.0,
            "function_hash": "237126485219913127008369546197861784848"
        }
    },
    {
        "source": "https://github.com/juce-framework/juce/commit/2e874e80cba0152201aff6a4d0dc407997d10a7f",
        "signature_version": "v1",
        "deprecated": false,
        "id": "CVE-2021-23521-1095d741",
        "target": {
            "file": "modules/juce_core/zip/juce_ZipFile.cpp"
        },
        "signature_type": "Line",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "5665146828299311367131662985033393450",
                "25705000018203975215230337355470258086",
                "73461143352547144272351347185771427613",
                "115105954260795451183459975315968406532",
                "217244814178410470630742754195289869085",
                "49084122028900548364993653296666858656",
                "325991889492344124971183810307317007165",
                "158767576336443612894225993343742284546",
                "22882037744203086060580223086712743160",
                "160593107989657383839657597257657288969",
                "213451794356186389434614993281912298275",
                "275721802318761377509861022008396111938",
                "130653500459608639864472418804361048119",
                "273332470345476517697735639630909816461",
                "260462639253294651763368097174421627806",
                "6020749457238924465845084673732165903",
                "153320649057292567536622638828076027496",
                "98871360293217199458224139798961620166",
                "272885099627383471393744008177406840849",
                "291575883478327668516045068826351348135",
                "154979891626412947699061347020712952638",
                "243963904254869942640995047314810898673",
                "212840248489521459102842670956752041279",
                "240427392179117427293706750928373018906",
                "230474873361751680400794394115815013594",
                "276369141589697939840954213595942450097",
                "219947248126034986284379597760536714776",
                "108809999214475554462129177081981798315",
                "131708057395091255140995409953012566600",
                "329777542193465666182838795792419497232",
                "201901353281578892610176125317185222332",
                "230657091421927173177949777420568947926",
                "91325379333541385178968899147732598831",
                "292963932828446528557640935761250622341",
                "13828876792834701556718117794312153713"
            ]
        }
    },
    {
        "source": "https://github.com/juce-framework/juce/commit/2e874e80cba0152201aff6a4d0dc407997d10a7f",
        "signature_version": "v1",
        "deprecated": false,
        "id": "CVE-2021-23521-15d35dc1",
        "target": {
            "function": "TemporaryFile::deleteTemporaryFile",
            "file": "modules/juce_core/files/juce_TemporaryFile.cpp"
        },
        "signature_type": "Function",
        "digest": {
            "length": 190.0,
            "function_hash": "330644850256258962130216906016415763780"
        }
    },
    {
        "source": "https://github.com/juce-framework/juce/commit/2e874e80cba0152201aff6a4d0dc407997d10a7f",
        "signature_version": "v1",
        "deprecated": false,
        "id": "CVE-2021-23521-27aa51cf",
        "target": {
            "file": "modules/juce_core/files/juce_TemporaryFile.cpp"
        },
        "signature_type": "Line",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "252897070295914309755168594136393890767",
                "330559751373960295323334258514495532823",
                "18584094889909008286008261321626697420",
                "94101849635669944803066779025124826108"
            ]
        }
    },
    {
        "source": "https://github.com/juce-framework/juce/commit/2e874e80cba0152201aff6a4d0dc407997d10a7f",
        "signature_version": "v1",
        "deprecated": false,
        "id": "CVE-2021-23521-583241be",
        "target": {
            "file": "modules/juce_core/zip/juce_ZipFile.h"
        },
        "signature_type": "Line",
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "313450786087896710849658816888521303545",
                "158873883966962821624702911924557038862",
                "198250517587726303670391863374999802557"
            ]
        }
    }
]