GHSA-vv77-66rf-pm86: Mpp Mpp Vulnerable To Gas Draining Vulnerability

HIGH
CWE-20
Published
Advisory Summary

GHSA-vv77-66rf-pm86 is a HIGH mpp vulnerable to gas draining vulnerability (CWE-20: Improper Input Validation) affecting Mpp libraries in the Hex ecosystem. The issue involves mpp vulnerable to gas draining with no limit. Remediation is available by upgrading affected packages to version 0.6.0.

GHSA-vv77-66rf-pm86 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-vv77-66rf-pm86
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-20: Improper Input Validation
Affected Product Mpp
Package Ecosystem Hex
Published Date
Last Updated

How to Fix GHSA-vv77-66rf-pm86

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

mpp fixed: 0.6.0
Upgrade mpp to 0.6.0
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 mpp

How to Check if You Are Affected

To determine whether your application is affected by GHSA-vv77-66rf-pm86, inspect your project dependencies for Mpp:

inspect dependencies for mpp

Analyze the terminal output to locate any version of Mpp in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.6.0), 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-20: Improper Input Validation, where the product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. In Mpp, 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

### Details When the server acts as the fee_payer, the `mpp` Elixir 0.4.0 does not validate `gas_limit`, `max_fee_per_gas` and `max_priority_fee_per_gas` before cosigning the client's fee-payer transaction. A malicious client embeds arbitrarily large `max_fee_per_gas` and `max_priority_fee_per_gas` values in the signed envelope. The server cosigns and broadcasts — paying those inflated gas costs from its own wallet based on the `effective_gas_price` calculated from the high `max_fee_per_gas` and `max_priority_fee_per_gas` set by the client. **Vulnerable function:** `cosign_fee_payer/3` in [`transaction.ex`](https://hex.pm/packages/mpp/0.4.0) around lines 229–262. ### PoC The PoC is provided below. It is configured to reproduce the attack on Tempo Moderate testnet within a Docker environment. Download the PoC and run: ```bash unzip mpp_elixir_PoC.zip cd mpp_elixir docker build -t mpp-elixir-gasdrain . docker run --rm mpp-elixir-gasdrain ``` There are more details in `mpp_elixir/README.md` ### Impact By draining the server's wallet, an attacker causes direct financial loss to the organization. Furthermore, if the server's funds are drained completely, legitimate clients will have their requests fail, as the server can no longer fund future transactions, effectively creating a Denial of Service (DoS) attack.

GHSA-vv77-66rf-pm86 Affected Mpp Versions

1 component(s)
Fixed Versions:
0.6.0
Product / Package Ecosystem Affected Versions Fixed Version
mpp
Hex
≥ 0.2.0
< 0.6.0
0.6.0

References

Frequently Asked Questions

What is GHSA-vv77-66rf-pm86?
GHSA-vv77-66rf-pm86 is a security vulnerability in Mpp involving mpp vulnerable to Gas Draining with no limit under CWE-20: Improper Input Validation.
Which Mpp versions are affected?
Affected versions include releases prior to 0.6.0 across affected packages: mpp.
What version fixes GHSA-vv77-66rf-pm86?
Upgrading to 0.6.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is mpp affected?
Yes, mpp is affected in releases prior to 0.6.0. Upgrade your dependency to 0.6.0 or later.
What CWE is associated with GHSA-vv77-66rf-pm86?
GHSA-vv77-66rf-pm86 is classified under CWE-20: Improper Input Validation (The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.).
How can I check Hex dependencies for GHSA-vv77-66rf-pm86?
Run the dependency tree command: 'inspect dependencies for mpp'. 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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vv77-66rf-pm86",
  "modified" : "2026-09-25T21:44:12Z",
  "published" : "2026-09-25T21:44:12Z",
  "aliases" : [ ],
  "summary" : "mpp vulnerable to Gas Draining with no limit",
  "details" : "### Details\nWhen the server acts as the fee_payer, the `mpp` Elixir 0.4.0 does not validate `gas_limit`, `max_fee_per_gas` and `max_priority_fee_per_gas` before cosigning the client's fee-payer transaction. A malicious client embeds arbitrarily large `max_fee_per_gas` and `max_priority_fee_per_gas` values in the signed envelope. The server cosigns and broadcasts — paying those inflated gas costs from its own wallet based on the `effective_gas_price` calculated from the high `max_fee_per_gas` and `max_priority_fee_per_gas` set by the client.\n\n**Vulnerable function:** `cosign_fee_payer/3` in [`transaction.ex`](https://hex.pm/packages/mpp/0.4.0) around lines 229–262.\n\n### PoC\nThe PoC is provided below. It is configured to reproduce the attack on Tempo Moderate testnet within a Docker environment. Download the PoC and run:\n```bash\nunzip mpp_elixir_PoC.zip\ncd mpp_elixir\ndocker build -t mpp-elixir-gasdrain .\ndocker run --rm mpp-elixir-gasdrain\n``` \nThere are more details in `mpp_elixir/README.md`\n\n### Impact\nBy draining the server's wallet, an attacker causes direct financial loss to the organization. Furthermore, if the server's funds are drained completely, legitimate clients will have their requests fail, as the server can no longer fund future transactions, effectively creating a Denial of Service (DoS) attack.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Hex",
      "name" : "mpp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.2.0"
      }, {
        "fixed" : "0.6.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ZenHive/mpp/security/advisories/GHSA-vv77-66rf-pm86"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ZenHive/mpp/commit/5d6338e2334084c5f2a78cfcca474830733ed7e8"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ZenHive/mpp"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ZenHive/mpp/releases/tag/v0.6.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-25T21:44:12Z",
    "nvd_published_at" : null
  }
}