CVE-2020-7694 Log Injection

2020-07-2711:25:12

snyk

www.cve.org

log injection

cve-2020-7694

uvicorn package

asni escape sequence

http request

urllib.parse.unquote

crafted urls

terminal emulator

CVSS3

3.7

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:U/RC:C

EPSS

0.001

Percentile

49.8%

JSON

This affects all versions of package uvicorn. The request logger provided by the package is vulnerable to ASNI escape sequence injection. Whenever any HTTP request is received, the default behaviour of uvicorn is to log its details to either the console or a log file. When attackers request crafted URLs with percent-encoded escape sequences, the logging component will log the URL after it’s been processed with urllib.parse.unquote, therefore converting any percent-encoded characters into their single-character equivalent, which can have special meaning in terminal emulators. By requesting URLs with crafted paths, attackers can: * Pollute uvicorn’s access logs, therefore jeopardising the integrity of such files. * Use ANSI sequence codes to attempt to interact with the terminal emulator that’s displaying the logs (either in real time or from a file).

CNA Affected

[
  {
    "product": "uvicorn",
    "vendor": "n/a",
    "versions": [
      {
        "lessThan": "unspecified",
        "status": "affected",
        "version": "0",
        "versionType": "custom"
      }
    ]
  }
]