CURL-CVE-2018-1000120

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Source
https://curl.se/docs/CVE-2018-1000120.html
Import Source
https://curl.se/docs/CURL-CVE-2018-1000120.json
JSON Data
https://api.test.osv.dev/v1/vulns/CURL-CVE-2018-1000120
Aliases
Published
2018-03-14T08:00:00Z
Modified
2024-06-07T13:53:51Z
Summary
FTP path trickery leads to NIL byte out of bounds write
Details

curl can be fooled into writing a zero byte out of bounds.

This bug can trigger when curl is told to work on an FTP URL, with the setting to only issue a single CWD command (--ftp-method singlecwd or the libcurl alternative CURLOPT_FTP_FILEMETHOD).

curl then URL-decodes the given path, calls strlen() on the result and deducts the length of the filename part to find the end of the directory within the buffer. It then writes a zero byte on that index, in a buffer allocated on the heap.

If the directory part of the URL contains a "%00" sequence, the directory length might end up shorter than the filename path, making the calculation size_t index = directory_len - filepart_len end up with a huge index variable for where the zero byte gets stored: heap_buffer[index] = 0. On several architectures that huge index wraps and works as a negative value, thus overwriting memory before the intended heap buffer.

By using different file part lengths and putting %00 in different places in the URL, an attacker that can control what paths a curl-using application uses can write that zero byte on different indexes.

Database specific 
{
    "package": "curl",
    "severity": "High",
    "CWE": {
        "desc": "Heap-based Buffer Overflow",
        "id": "CWE-122"
    },
    "last_affected": "7.58.0",
    "URL": "https://curl.se/docs/CVE-2018-1000120.json",
    "affects": "both",
    "www": "https://curl.se/docs/CVE-2018-1000120.html"
}
References
Credits
    • Duy Phan Thanh - FINDER
    • Daniel Stenberg - REMEDIATION_DEVELOPER

Affected packages

Git / github.com/curl/curl.git

Affected ranges

Type
SEMVER
Events
Introduced
7.12.3
Fixed
7.59.0
Type
GIT
Repo
https://github.com/curl/curl.git
Events
Introduced
6e1e9caa32da099569bb95e64faf0b5f3cf103b5
Fixed
535432c0adb62fe167ec09621500470b6fa4eb0f

Affected versions

7.*

7.12.3
7.13.0
7.13.1
7.13.2
7.14.0
7.14.1
7.15.0
7.15.1
7.15.2
7.15.3
7.15.4
7.15.5
7.16.0
7.16.1
7.16.2
7.16.3
7.16.4
7.17.0
7.17.1
7.18.0
7.18.1
7.18.2
7.19.0
7.19.1
7.19.2
7.19.3
7.19.4
7.19.5
7.19.6
7.19.7
7.20.0
7.20.1
7.21.0
7.21.1
7.21.2
7.21.3
7.21.4
7.21.5
7.21.6
7.21.7
7.22.0
7.23.0
7.23.1
7.24.0
7.25.0
7.26.0
7.27.0
7.28.0
7.28.1
7.29.0
7.30.0
7.31.0
7.32.0
7.33.0
7.34.0
7.35.0
7.36.0
7.37.0
7.37.1
7.38.0
7.39.0
7.40.0
7.41.0
7.42.0
7.42.1
7.43.0
7.44.0
7.45.0
7.46.0
7.47.0
7.47.1
7.48.0
7.49.0
7.49.1
7.50.0
7.50.1
7.50.2
7.50.3
7.51.0
7.52.0
7.52.1
7.53.0
7.53.1
7.54.0
7.54.1
7.55.0
7.55.1
7.56.0
7.56.1
7.57.0
7.58.0

Database specific 

{
    "vanir_signatures": [
        {
            "id": "CURL-CVE-2018-1000120-1a41fdc7",
            "deprecated": false,
            "signature_version": "v1",
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                ],
                "threshold": 0.9
            },
            "source": "https://github.com/curl/curl.git/commit/535432c0adb62fe167ec09621500470b6fa4eb0f",
            "signature_type": "Line",
            "target": {
                "file": "lib/ftp.c"
            }
        },
        {
            "id": "CURL-CVE-2018-1000120-3930517d",
            "deprecated": false,
            "signature_version": "v1",
            "digest": {
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                "length": 925.0
            },
            "source": "https://github.com/curl/curl.git/commit/535432c0adb62fe167ec09621500470b6fa4eb0f",
            "signature_type": "Function",
            "target": {
                "file": "lib/ftp.c",
                "function": "ftp_state_list"
            }
        },
        {
            "id": "CURL-CVE-2018-1000120-3dc55c90",
            "deprecated": false,
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            "signature_type": "Function",
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            "digest": {
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            "source": "https://github.com/curl/curl.git/commit/535432c0adb62fe167ec09621500470b6fa4eb0f",
            "signature_type": "Function",
            "target": {
                "file": "lib/ftp.c",
                "function": "ftp_done"
            }
        }
    ]
}