CVE-2021-36155: Github.com/grpc/grpc swift Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-rxmj-hg9v-vp3p
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CVSS 7.5
CWE-120 CWE-770
Published
Advisory Summary

CVE-2021-36155 is a HIGH (CVSS 7.5) remote code execution vulnerability (CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')) affecting Github.com/grpc/grpc swift libraries in the SwiftURL ecosystem. The issue involves uncontrolled resource consumption in lengthprefixedmessagereader. Remediation is available by upgrading affected packages to version 1.2.0.

CVE-2021-36155 at a Glance

CVE Identifier CVE-2021-36155
GHSA Identifier GHSA-rxmj-hg9v-vp3p
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Affected Product Github.com/grpc/grpc swift
Package Ecosystem SwiftURL
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-2021-36155

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

github.com/grpc/grpc-swift fixed: 1.2.0 
Upgrade github.com/grpc/grpc-swift to 1.2.0
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 github.com/grpc/grpc-swift

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-36155, inspect your project dependencies for Github.com/grpc/grpc swift:

inspect dependencies for github.com/grpc/grpc-swift

Analyze the terminal output to locate any version of Github.com/grpc/grpc swift in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.2.0), 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-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'), where the product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer. In Github.com/grpc/grpc swift, 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

### Impact Affected gRPC Swift clients and servers are vulnerable to uncontrolled resource consumption attacks. Excessive memory may be allocated when parsing messages. This can lead to a denial of service. ### Patches The problem has been fixed in 1.2.0. ### Workarounds No workaround is available. Users must upgrade.

CVE-2021-36155 Affected Github.com/grpc/grpc swift Versions

1 component(s)
Fixed Versions:
1.2.0
Product / Package Ecosystem Affected Versions Fixed Version
github.com/grpc/grpc-swift
 SwiftURL
< 1.2.0
1.2.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/grpc/grpc-swift/security/advisories/GHSA-rxmj-hg9v-vp3p
NVD — CVE-2021-36155 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-36155
bugs.chromium.org/p/oss-fuzz/issues/d... WEB
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35303
Github.com/grpc/grpc swift Source Repository REPOSITORY
https://github.com/grpc/grpc-swift
Github.com/grpc/grpc swift Release RELEASE
https://github.com/grpc/grpc-swift/releases/tag/1.2.0

Frequently Asked Questions

What is CVE-2021-36155?
CVE-2021-36155 is a security vulnerability in Github.com/grpc/grpc swift involving Uncontrolled Resource Consumption in LengthPrefixedMessageReader under CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow').
Which Github.com/grpc/grpc swift versions are affected?
Affected versions include releases prior to 1.2.0 across affected packages: github.com/grpc/grpc-swift.
What version fixes CVE-2021-36155?
Upgrading to 1.2.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/grpc/grpc-swift affected?
Yes, github.com/grpc/grpc-swift is affected in releases prior to 1.2.0. Upgrade your dependency to 1.2.0 or later.
What is the CVSS score of CVE-2021-36155?
CVE-2021-36155 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-2021-36155?
CVE-2021-36155 is classified under CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') (The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.).
How can I check SwiftURL dependencies for CVE-2021-36155?
Run the dependency tree command: 'inspect dependencies for github.com/grpc/grpc-swift'. 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-rxmj-hg9v-vp3p",
  "modified" : "2023-06-09T19:32:11Z",
  "published" : "2023-06-09T19:32:11Z",
  "aliases" : [ "CVE-2021-36155" ],
  "summary" : "Uncontrolled Resource Consumption in LengthPrefixedMessageReader",
  "details" : "### Impact\n\nAffected gRPC Swift clients and servers are vulnerable to uncontrolled resource consumption attacks. Excessive memory may be allocated when parsing messages. This can lead to a denial of service.\n\n### Patches\n\nThe problem has been fixed in 1.2.0.\n\n### Workarounds\n\nNo workaround is available. Users must upgrade.",
  "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" : "SwiftURL",
      "name" : "github.com/grpc/grpc-swift"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/grpc/grpc-swift/security/advisories/GHSA-rxmj-hg9v-vp3p"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-36155"
  }, {
    "type" : "WEB",
    "url" : "https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35303"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/grpc/grpc-swift"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/grpc/grpc-swift/releases/tag/1.2.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-120", "CWE-770" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-06-09T19:32:11Z",
    "nvd_published_at" : "2021-07-09T12:15:00Z"
  }
}