CVE-2019-15547: Ncurses Mishandling Of Format Strings Vulnerability

HIGH
Advisory Identifier: GHSA-32v7-ghpr-c8hg
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CVSS 7.5
CWE-134
Published
Advisory Summary

CVE-2019-15547 is a HIGH (CVSS 7.5) mishandling of format strings vulnerability (CWE-134: Use of Externally-Controlled Format String) affecting Ncurses libraries in the crates.io ecosystem. The issue involves mishandling of format strings in ncurses. Remediation is available in the latest vendor maintenance releases.

CVE-2019-15547 at a Glance

CVE Identifier CVE-2019-15547
GHSA Identifier GHSA-32v7-ghpr-c8hg
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-134: Use of Externally-Controlled Format String
Affected Product Ncurses
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:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).

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 High (I:H)
Availability None (A:N)

How to Fix CVE-2019-15547

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

ncurses fixed: Latest secure release 
Upgrade ncurses to Latest secure release
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 ncurses

How to Check if You Are Affected

To determine whether your application is affected by CVE-2019-15547, inspect your project dependencies for Ncurses:

inspect dependencies for ncurses

Analyze the terminal output to locate any version of Ncurses in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), 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-134: Use of Externally-Controlled Format String, where the product uses a function that accepts a format string as an argument, but the format string originates from an external source. In Ncurses, 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

ncurses exposes functions from the ncurses library which: * Pass buffers without length to C functions that may write an arbitrary amount of data, leading to a buffer overflow. (instr, mvwinstr, etc) * Passes rust &str to strings expecting C format arguments, allowing hostile input to execute a format string attack, which trivially allows writing arbitrary data to stack memory (functions in the printw family).

CVE-2019-15547 Affected Ncurses Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
ncurses
 crates.io
≤ 5.101.0

References

NVD — CVE-2019-15547 NVD
https://nvd.nist.gov/vuln/detail/CVE-2019-15547
Ncurses Source Repository REPOSITORY
https://github.com/RustSec/advisory-db/issues/106
Ncurses Source Repository REPOSITORY
https://github.com/jeaye/ncurses-rs/issues/172
Ncurses Source Repository REPOSITORY
https://github.com/jeaye/ncurses-rs
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2019-0006.html

Frequently Asked Questions

What is CVE-2019-15547?
CVE-2019-15547 is a security vulnerability in Ncurses involving Mishandling of format strings in ncurses under CWE-134: Use of Externally-Controlled Format String.
Which Ncurses versions are affected?
Affected versions include releases prior to current release patches across affected packages: ncurses.
What version fixes CVE-2019-15547?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is ncurses affected?
Yes, ncurses is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2019-15547?
CVE-2019-15547 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2019-15547?
CVE-2019-15547 is classified under CWE-134: Use of Externally-Controlled Format String (The product uses a function that accepts a format string as an argument, but the format string originates from an external source.).
How can I check crates.io dependencies for CVE-2019-15547?
Run the dependency tree command: 'inspect dependencies for ncurses'. 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-32v7-ghpr-c8hg",
  "modified" : "2023-06-13T18:30:35Z",
  "published" : "2021-08-25T20:58:47Z",
  "aliases" : [ "CVE-2019-15547" ],
  "summary" : "Mishandling of format strings in ncurses",
  "details" : "ncurses exposes functions from the ncurses library which:\n* Pass buffers without length to C functions that may write an arbitrary amount of data, leading to a buffer overflow. (instr, mvwinstr, etc)\n* Passes rust &str to strings expecting C format arguments, allowing hostile input to execute a format string attack, which trivially allows writing arbitrary data to stack memory (functions in the printw family).\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "ncurses"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "5.101.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2019-15547"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/RustSec/advisory-db/issues/106"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/jeaye/ncurses-rs/issues/172"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/jeaye/ncurses-rs"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2019-0006.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-134" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-18T17:45:13Z",
    "nvd_published_at" : null
  }
}