CVE-2020-35901: Actix http Use-after-free Vulnerability

HIGH
Advisory Identifier: GHSA-v3j6-xf77-8r9c
Share
CVSS 7.5
CWE-416
Published
Advisory Summary

CVE-2020-35901 is a HIGH (CVSS 7.5) use-after-free vulnerability (CWE-416: Use After Free) affecting Actix http libraries in the crates.io ecosystem. The issue involves use-after-free in actix-http. Remediation is available by upgrading affected packages to version 2.0.0.

CVE-2020-35901 at a Glance

CVE Identifier CVE-2020-35901
GHSA Identifier GHSA-v3j6-xf77-8r9c
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-416: Use After Free
Affected Product Actix http
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2020-35901

To remediate this vulnerability, upgrade all affected Actix http dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

actix-http fixed: 2.0.0 
Upgrade actix-http to 2.0.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for actix-http

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-35901, inspect your project dependencies for Actix http:

inspect dependencies for actix-http

Analyze the terminal output to locate any version of Actix http in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.0.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-416: Use After Free, where the product reuses or references memory after it has been freed. at some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. In Actix http, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

An issue was discovered in the actix-http crate before 2.0.0-alpha.1 for Rust. There is a use-after-free in BodyStream.

CVE-2020-35901 Affected Actix http Versions

1 component(s)
Fixed Versions:
2.0.0
Product / Package Ecosystem Affected Versions Fixed Version
actix-http
 crates.io
< 2.0.0
2.0.0

References

NVD — CVE-2020-35901 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-35901
Actix http Source Repository REPOSITORY
https://github.com/actix/actix-web/issues/1321
Actix http Source Repository REPOSITORY
https://github.com/actix/actix-web
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2020-0048.html

Frequently Asked Questions

What is CVE-2020-35901?
CVE-2020-35901 is a security vulnerability in Actix http involving Use-after-free in actix-http under CWE-416: Use After Free.
Which Actix http versions are affected?
Affected versions include releases prior to 2.0.0 across affected packages: actix-http.
What version fixes CVE-2020-35901?
Upgrading to 2.0.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is actix-http affected?
Yes, actix-http is affected in releases prior to 2.0.0. Upgrade your dependency to 2.0.0 or later.
What is the CVSS score of CVE-2020-35901?
CVE-2020-35901 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2020-35901?
CVE-2020-35901 is classified under CWE-416: Use After Free (The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.).
How can I check crates.io dependencies for CVE-2020-35901?
Run the dependency tree command: 'inspect dependencies for actix-http'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-v3j6-xf77-8r9c",
  "modified" : "2021-08-19T20:51:41Z",
  "published" : "2021-08-25T20:49:39Z",
  "aliases" : [ "CVE-2020-35901" ],
  "summary" : "Use-after-free in actix-http",
  "details" : "An issue was discovered in the actix-http crate before 2.0.0-alpha.1 for Rust. There is a use-after-free in BodyStream.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "actix-http"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-35901"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/actix/actix-web/issues/1321"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/actix/actix-web"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2020-0048.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-416" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-19T20:51:41Z",
    "nvd_published_at" : null
  }
}