CVE-2021-45703: Tectonic xdv Remote Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-qwvx-c8j7-5g75
Share
CVSS 9.8
CWE-908
Published
Advisory Summary

CVE-2021-45703 is a CRITICAL (CVSS 9.8) remote code execution vulnerability (CWE-908: Use of Uninitialized Resource) affecting Tectonic xdv libraries in the crates.io ecosystem. The issue involves use of uninitialized resource in tectonic_xdv. Remediation is available by upgrading affected packages to version 0.1.12.

CVE-2021-45703 at a Glance

CVE Identifier CVE-2021-45703
GHSA Identifier GHSA-qwvx-c8j7-5g75
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-908: Use of Uninitialized Resource
Affected Product Tectonic xdv
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 9.8

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:H/I:H/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 High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2021-45703

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

tectonic_xdv fixed: 0.1.12 
Upgrade tectonic_xdv to 0.1.12
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 tectonic_xdv

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-45703, inspect your project dependencies for Tectonic xdv:

inspect dependencies for tectonic_xdv

Analyze the terminal output to locate any version of Tectonic xdv in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.1.12), 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-908: Use of Uninitialized Resource, where the product uses or accesses a resource that has not been initialized. In Tectonic xdv, 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

Affected versions of this crate passes an uninitialized buffer to a user-provided Read implementation. Arbitrary Read implementations can read from the uninitialized buffer (memory exposure) and also can return incorrect number of bytes written to the buffer. Reading from uninitialized memory produces undefined values that can quickly invoke undefined behavior. The problem was fixed in commit `cdff034` by zero-initializing the buffer before passing it to a user-provided Read implementation.

CVE-2021-45703 Affected Tectonic xdv Versions

1 component(s)
Fixed Versions:
0.1.12
Product / Package Ecosystem Affected Versions Fixed Version
tectonic_xdv
 crates.io
< 0.1.12
0.1.12

References

NVD — CVE-2021-45703 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-45703
Tectonic xdv Source Repository REPOSITORY
https://github.com/tectonic-typesetting/tectonic/issues/752
Security Fix Commit FIX COMMIT
https://github.com/tectonic-typesetting/tectonic/commit/cdff034e6d93cdfdafd13d8c6956e22fa5a57b79
Tectonic xdv Source Repository REPOSITORY
https://github.com/tectonic-typesetting/tectonic
raw.githubusercontent.com/rustsec/advisory-db... WEB
https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/tectonic_xdv/RUSTSEC-2021-0112.md
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2021-0112.html

Frequently Asked Questions

What is CVE-2021-45703?
CVE-2021-45703 is a security vulnerability in Tectonic xdv involving Use of Uninitialized Resource in tectonic_xdv under CWE-908: Use of Uninitialized Resource.
Which Tectonic xdv versions are affected?
Affected versions include releases prior to 0.1.12 across affected packages: tectonic_xdv.
What version fixes CVE-2021-45703?
Upgrading to 0.1.12 (or the latest patched release for your respective branch) resolves the vulnerability.
Is tectonic_xdv affected?
Yes, tectonic_xdv is affected in releases prior to 0.1.12. Upgrade your dependency to 0.1.12 or later.
What is the CVSS score of CVE-2021-45703?
CVE-2021-45703 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2021-45703?
CVE-2021-45703 is classified under CWE-908: Use of Uninitialized Resource (The product uses or accesses a resource that has not been initialized.).
How can I check crates.io dependencies for CVE-2021-45703?
Run the dependency tree command: 'inspect dependencies for tectonic_xdv'. 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-qwvx-c8j7-5g75",
  "modified" : "2023-06-13T22:01:48Z",
  "published" : "2022-01-06T22:09:19Z",
  "aliases" : [ "CVE-2021-45703" ],
  "summary" : "Use of Uninitialized Resource in tectonic_xdv",
  "details" : "Affected versions of this crate passes an uninitialized buffer to a user-provided Read implementation.\n\nArbitrary Read implementations can read from the uninitialized buffer (memory exposure) and also can return incorrect number of bytes written to the buffer. Reading from uninitialized memory produces undefined values that can quickly invoke undefined behavior.\n\nThe problem was fixed in commit `cdff034` by zero-initializing the buffer before passing it to a user-provided Read implementation.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "tectonic_xdv"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.1.12"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-45703"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tectonic-typesetting/tectonic/issues/752"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tectonic-typesetting/tectonic/commit/cdff034e6d93cdfdafd13d8c6956e22fa5a57b79"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tectonic-typesetting/tectonic"
  }, {
    "type" : "WEB",
    "url" : "https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/tectonic_xdv/RUSTSEC-2021-0112.md"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2021-0112.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-908" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-01-05T23:41:34Z",
    "nvd_published_at" : "2021-12-27T00:15:00Z"
  }
}