CVE-2020-28493 Regular Expression Denial of Service (ReDoS)

2021-02-0100:00:00

snyk

www.cve.org

5.3 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

LOW

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

5.8 Medium

AI Score

Confidence

High

0.002 Low

EPSS

Percentile

57.1%

JSON

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the _punctuation_re regex operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

CNA Affected

[
  {
    "product": "jinja2",
    "vendor": "n/a",
    "versions": [
      {
        "lessThan": "unspecified",
        "status": "affected",
        "version": "0.0.0",
        "versionType": "custom"
      },
      {
        "lessThan": "2.11.3",
        "status": "affected",
        "version": "unspecified",
        "versionType": "custom"
      }
    ]
  }
]