CURL-CVE-2016-8617

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Source
https://curl.se/docs/CVE-2016-8617.html
Import Source
https://curl.se/docs/CURL-CVE-2016-8617.json
JSON Data
https://api.test.osv.dev/v1/vulns/CURL-CVE-2016-8617
Aliases
Published
2016-11-02T08:00:00Z
Modified
2026-05-18T13:46:16.636214Z
Summary
OOB write via unchecked multiplication
Details

In libcurl's base64 encode function, the output buffer is allocated as follows without any checks on insize:

malloc( insize * 4 / 3 + 4 )

On systems with 32-bit addresses in userspace (e.g. x86, ARM, x32), the multiplication in the expression wraps around if insize is at least 1GB of data. If this happens, an undersized output buffer is allocated, but the full result is written, thus causing the memory behind the output buffer to be overwritten.

If a username is set directly via CURLOPT_USERNAME (or curl's -u, --user option), this vulnerability can be triggered. The name has to be at least 512MB big in a 32-bit system.

Systems with 64-bit versions of the size_t type are not affected by this issue.

Database specific 
{
    "URL": "https://curl.se/docs/CVE-2016-8617.json",
    "www": "https://curl.se/docs/CVE-2016-8617.html",
    "CWE": {
        "id": "CWE-131",
        "desc": "Incorrect Calculation of Buffer Size"
    },
    "package": "curl",
    "severity": "Medium",
    "affects": "both",
    "last_affected": "7.50.3"
}
References
Credits
    • Cure53 - FINDER
    • Daniel Stenberg - REMEDIATION_DEVELOPER

Affected packages

Git / github.com/curl/curl.git

Affected ranges

Type
SEMVER
Events
Introduced
7.8.1
Fixed
7.51.0
Type
GIT
Repo
https://github.com/curl/curl.git
Events
Introduced
00b00c693127d9e3a4eedce4c8cdf6e87087192d
Fixed
efd24d57426bd77c9b5860e6b297904703750412

Affected versions

7.*
7.10
7.10.1
7.10.2
7.10.3
7.10.4
7.10.5
7.10.6
7.10.7
7.10.8
7.11.0
7.11.1
7.11.2
7.12.0
7.12.1
7.12.2
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
7.8.1
7.9
7.9.1
7.9.2
7.9.3
7.9.4
7.9.5
7.9.6
7.9.7
7.9.8
Other
before_ftp_statemachine
before_urldata_rename
curl-7_10
curl-7_10_1
curl-7_10_2
curl-7_10_3
curl-7_10_4
curl-7_10_5
curl-7_10_6
curl-7_10_7
curl-7_10_8
curl-7_11_0
curl-7_11_1
curl-7_11_2
curl-7_12_0
curl-7_12_1
curl-7_12_2
curl-7_12_3
curl-7_13_0
curl-7_13_1
curl-7_13_2
curl-7_14_0
curl-7_14_1
curl-7_15_0
curl-7_15_1
curl-7_15_2
curl-7_15_3
curl-7_15_4
curl-7_15_5
curl-7_15_6-prepipeline
curl-7_16_0
curl-7_16_1
curl-7_16_2
curl-7_16_3
curl-7_16_4
curl-7_17_0
curl-7_17_0-preldapfix
curl-7_17_1
curl-7_18_0
curl-7_18_1
curl-7_18_2
curl-7_19_0
curl-7_19_1
curl-7_19_2
curl-7_19_3
curl-7_19_4
curl-7_19_5
curl-7_19_6
curl-7_19_7
curl-7_20_0
curl-7_20_1
curl-7_21_0
curl-7_21_1
curl-7_21_2
curl-7_21_3
curl-7_21_4
curl-7_21_5
curl-7_21_6
curl-7_21_7
curl-7_22_0
curl-7_23_0
curl-7_23_1
curl-7_25_0
curl-7_26_0
curl-7_27_0
curl-7_28_0
curl-7_28_1
curl-7_29_0
curl-7_30_0
curl-7_31_0
curl-7_32_0
curl-7_33_0
curl-7_34_0
curl-7_35_0
curl-7_36_0
curl-7_37_0
curl-7_37_1
curl-7_38_0
curl-7_39_0
curl-7_40_0
curl-7_41_0
curl-7_42_0
curl-7_43_0
curl-7_44_0
curl-7_45_0
curl-7_46_0
curl-7_47_0
curl-7_47_1
curl-7_48_0
curl-7_49_0
curl-7_49_1
curl-7_50_0
curl-7_50_1
curl-7_50_2
curl-7_50_3
curl-7_8_1
curl-7_8_1-pre3
curl-7_9
curl-7_9_1
curl-7_9_2
curl-7_9_3
curl-7_9_3-pre1
curl-7_9_3-pre2
curl-7_9_3-pre3
curl-7_9_4
curl-7_9_5
curl-7_9_5-pre2
curl-7_9_5-pre4
curl-7_9_6
curl-7_9_7
curl-7_9_7-pre2
curl-7_9_8

Database specific

vanir_signatures_modified 
"2026-05-18T13:46:16Z"
source 
"https://curl.se/docs/CURL-CVE-2016-8617.json"
vanir_signatures 
[
    {
        "digest": {
            "threshold": 0.9,
            "line_hashes": [
                "330189580163966104573813564222353944049",
                "251539769233120043131544711578422921980",
                "110228242315381419112297075161928694033"
            ]
        },
        "deprecated": false,
        "id": "CURL-CVE-2016-8617-36b10dd2",
        "source": "https://github.com/curl/curl.git/commit/efd24d57426bd77c9b5860e6b297904703750412",
        "signature_version": "v1",
        "signature_type": "Line",
        "target": {
            "file": "lib/base64.c"
        }
    },
    {
        "digest": {
            "length": 1573.0,
            "function_hash": "339377937843865329842231627374085505111"
        },
        "deprecated": false,
        "id": "CURL-CVE-2016-8617-acca1aa4",
        "source": "https://github.com/curl/curl.git/commit/efd24d57426bd77c9b5860e6b297904703750412",
        "signature_version": "v1",
        "signature_type": "Function",
        "target": {
            "file": "lib/base64.c",
            "function": "base64_encode"
        }
    }
]