BlackTreeCVE Intelligence
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Full vulnerability report · 2021
CVE-2021-42771High confidence

Babel.Locale in Babel before 2.9.1 allows attackers to load arbitrary locale .dat files (containing serialized Python objects) via directory traversal, leading to code execution

Unknown · Unknown

7.8HighCVSS 3.1
Recommended action
Within 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:High, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.77% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

7 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · mainpy3-babelVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.9.1-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.22v3.22 · mainpy3-babelVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.9.1-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.21v3.21 · mainpy3-babelVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.9.1-r0Alpine Security Database ↗Source updated 3 Oct 2026
Debian trixietrixie · sourcepython-babelVendor fix publishedDebian records a fixed source-package version for this release.2.8.0+dfsg.1-7Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcepython-babelVendor fix publishedDebian records a fixed source-package version for this release.2.8.0+dfsg.1-7Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcepython-babelVendor fix publishedDebian records a fixed source-package version for this release.2.8.0+dfsg.1-7Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcepython-babelVendor fix publishedDebian records a fixed source-package version for this release.2.8.0+dfsg.1-7Debian Security Tracker ↗Source updated 5 Oct 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-0032

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Babel.Locale in Babel before 2.9.1 allows attackers to load arbitrary locale .dat files (containing serialized Python objects) via directory traversal, leading to code execution.

What

Babel.Locale in Babel before 2.9.1 allows attackers to load arbitrary locale .dat files (containing serialized Python objects) via directory traversal, leading to code execution.

Why

Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Babel.Locale in Babel before 2.9.1 allows attackers to load arbitrary locale .dat files (containing serialized Python objects) via directory traversal, leading to code execution.

Why

Attacker-controlled path data is not constrained to the intended directory before the application accesses a file.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
local access → Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-22 ↗

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
CWE-22Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2022-0571Red Hat Enterprise Linux: Mehrere Schwachstellen

Ein entfernter, anonymer, authentisierter oder lokaler Angreifer kann mehrere Schwachstellen in Red Hat Enterprise Linux ausnutzen, um einen Cross-Site-Scripting-Angriff durchzuführen, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand herbeizuführen, Sicherheitsmaßnahmen zu umgehen, beliebigen Code auszuführen, Dateien zu manipulieren und einen nicht spezifizierten Angriff durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20211027Security Bulletin 27 Oct 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 27 Oct 2021, published on 27 October 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0395Multiples vulnérabilités dans les produits IBM

g/CVERecord?id=CVE-2021-33928 Référence CVE CVE-2021-33929 https://www.cve.org/CVERecord?id=CVE-2021-33929 Référence CVE CVE-2021-33930 https://www.cve.org/CVERecord?id=CVE-2021-33930 Référence CVE CVE-2021-33938 https://www.cve.org/CVERecord?id=CVE-2021-33938 Référence CVE CVE-2021-3426 https://www.cve.org/CVERecord?id=CVE-2021-3426 Référence CVE CVE-2021-3572 https://www.cve.org/CVERecord?id=CVE-2021-3572 Référence CVE CVE-2021-3733 https://www.cve.org/CVERecord?id=CVE-2021-3733 Référence CVE CVE-2021-3737 https://www.cve.org/CVERecord?id=CVE-2021-3737 Référence CVE CVE-2021-4189 https://www.cve.org/CVERecord?id=CVE-2021-4189 Référence CVE CVE-2021-42771 https://www.cve.org/CVERecord?id=CVE-2021-42771 Référence CVE CVE-2021-43618 https://www.cve.org/CVERecord?id=CVE-2021-43618 Référence CVE CVE-2021-43818 https://www.cve.org/CVERecord?id=CVE-2021-43818 Référence CVE CVE-2021-44568 https://www.cve.org/CVERecord?id=CVE-2021-44568 Référence CVE CVE-2021-46877 https://www.cve.org/CVERecord?id=CVE-2021-46877 Référence CVE CVE-2022-1705 https://www.cve.org/CVERecord?id=CVE-2022-1705 Référence CVE CVE-2022-2255 https://www.cve.org/CVERecord?id=CVE-2022-2255 Référence CVE CVE-2022-40897 https://www.cve.org/CVERecord?id=CVE-2022-40897 Référence CVE CVE-2022-42919 https://www.cve.org/CVERecord?id=CVE-

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0326Multiples vulnérabilités dans les produits VMware

org/CVERecord?id=CVE-2021-33115 Référence CVE CVE-2021-33139 https://www.cve.org/CVERecord?id=CVE-2021-33139 Référence CVE CVE-2021-33155 https://www.cve.org/CVERecord?id=CVE-2021-33155 Référence CVE CVE-2021-3714 https://www.cve.org/CVERecord?id=CVE-2021-3714 Référence CVE CVE-2021-3735 https://www.cve.org/CVERecord?id=CVE-2021-3735 Référence CVE CVE-2021-3773 https://www.cve.org/CVERecord?id=CVE-2021-3773 Référence CVE CVE-2021-3826 https://www.cve.org/CVERecord?id=CVE-2021-3826 Référence CVE CVE-2021-3864 https://www.cve.org/CVERecord?id=CVE-2021-3864 Référence CVE CVE-2021-4095 https://www.cve.org/CVERecord?id=CVE-2021-4095 Référence CVE CVE-2021-42771 https://www.cve.org/CVERecord?id=CVE-2021-42771 Référence CVE CVE-2021-44532 https://www.cve.org/CVERecord?id=CVE-2021-44532 Référence CVE CVE-2021-44534 https://www.cve.org/CVERecord?id=CVE-2021-44534 Référence CVE CVE-2021-45261 https://www.cve.org/CVERecord?id=CVE-2021-45261 Référence CVE CVE-2021-46195 https://www.cve.org/CVERecord?id=CVE-2021-46195 Référence CVE CVE-2021-47432 https://www.cve.org/CVERecord?id=CVE-2021-47432 Référence CVE CVE-2021-47658 https://www.cve.org/CVERecord?id=CVE-2021-47658 Référence CVE CVE-2022-0400 https://www.cve.org/CVERecord?id=CVE-2022-0400 Référence CVE CVE-2022-0480 https://www.cve.org/CVERecord?id=CVE

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0316Multiples vulnérabilités dans les produits VMware

org/CVERecord?id=CVE-2021-33115 Référence CVE CVE-2021-33139 https://www.cve.org/CVERecord?id=CVE-2021-33139 Référence CVE CVE-2021-33155 https://www.cve.org/CVERecord?id=CVE-2021-33155 Référence CVE CVE-2021-3714 https://www.cve.org/CVERecord?id=CVE-2021-3714 Référence CVE CVE-2021-3735 https://www.cve.org/CVERecord?id=CVE-2021-3735 Référence CVE CVE-2021-3773 https://www.cve.org/CVERecord?id=CVE-2021-3773 Référence CVE CVE-2021-3826 https://www.cve.org/CVERecord?id=CVE-2021-3826 Référence CVE CVE-2021-3864 https://www.cve.org/CVERecord?id=CVE-2021-3864 Référence CVE CVE-2021-4095 https://www.cve.org/CVERecord?id=CVE-2021-4095 Référence CVE CVE-2021-42771 https://www.cve.org/CVERecord?id=CVE-2021-42771 Référence CVE CVE-2021-44532 https://www.cve.org/CVERecord?id=CVE-2021-44532 Référence CVE CVE-2021-44534 https://www.cve.org/CVERecord?id=CVE-2021-44534 Référence CVE CVE-2021-45261 https://www.cve.org/CVERecord?id=CVE-2021-45261 Référence CVE CVE-2021-46195 https://www.cve.org/CVERecord?id=CVE-2021-46195 Référence CVE CVE-2021-47432 https://www.cve.org/CVERecord?id=CVE-2021-47432 Référence CVE CVE-2021-47658 https://www.cve.org/CVERecord?id=CVE-2021-47658 Référence CVE CVE-2022-0400 https://www.cve.org/CVERecord?id=CVE-2022-0400 Référence CVE CVE-2022-0480 https://www.cve.org/CVERecord?id=CVE

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0903Multiples vulnérabilités dans les produits IBM

IBM 7173420 du 17 octobre 2024 https://www.ibm.com/support/pages/node/7173420 Bulletin de sécurité IBM 7173421 du 17 octobre 2024 https://www.ibm.com/support/pages/node/7173421 Référence CVE CVE-2018-1311 https://www.cve.org/CVERecord?id=CVE-2018-1311 Référence CVE CVE-2020-25219 https://www.cve.org/CVERecord?id=CVE-2020-25219 Référence CVE CVE-2020-26137 https://www.cve.org/CVERecord?id=CVE-2020-26137 Référence CVE CVE-2020-26154 https://www.cve.org/CVERecord?id=CVE-2020-26154 Référence CVE CVE-2020-26555 https://www.cve.org/CVERecord?id=CVE-2020-26555 Référence CVE CVE-2020-7212 https://www.cve.org/CVERecord?id=CVE-2020-7212 Référence CVE CVE-2021-42771 https://www.cve.org/CVERecord?id=CVE-2021-42771 Référence CVE CVE-2021-45429 https://www.cve.org/CVERecord?id=CVE-2021-45429 Référence CVE CVE-2021-46909 https://www.cve.org/CVERecord?id=CVE-2021-46909 Référence CVE CVE-2021-46972 https://www.cve.org/CVERecord?id=CVE-2021-46972 Référence CVE CVE-2021-47069 https://www.cve.org/CVERecord?id=CVE-2021-47069 Référence CVE CVE-2021-47073 https://www.cve.org/CVERecord?id=CVE-2021-47073 Référence CVE CVE-2021-47236 https://www.cve.org/CVERecord?id=CVE-2021-47236 Référence CVE CVE-2021-47310 https://www.cve.org/CVERecord?id=CVE-2021-47310 Référence CVE CVE-2021-47311 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-916Multiples vulnérabilités dans les produits Juniper

CVERecord?id=CVE-2021-37576 Référence CVE CVE-2021-3765 https://www.cve.org/CVERecord?id=CVE-2021-3765 Référence CVE CVE-2021-37750 https://www.cve.org/CVERecord?id=CVE-2021-37750 Référence CVE CVE-2021-4034 https://www.cve.org/CVERecord?id=CVE-2021-4034 Référence CVE CVE-2021-4155 https://www.cve.org/CVERecord?id=CVE-2021-4155 Référence CVE CVE-2021-4160 https://www.cve.org/CVERecord?id=CVE-2021-4160 Référence CVE CVE-2021-41617 https://www.cve.org/CVERecord?id=CVE-2021-41617 Référence CVE CVE-2021-42550 https://www.cve.org/CVERecord?id=CVE-2021-42550 Référence CVE CVE-2021-42574 https://www.cve.org/CVERecord?id=CVE-2021-42574 Référence CVE CVE-2021-42771 https://www.cve.org/CVERecord?id=CVE-2021-42771 Référence CVE CVE-2021-43527 https://www.cve.org/CVERecord?id=CVE-2021-43527 Référence CVE CVE-2021-45417 https://www.cve.org/CVERecord?id=CVE-2021-45417 Référence CVE CVE-2021-45960 https://www.cve.org/CVERecord?id=CVE-2021-45960 Référence CVE CVE-2021-46143 https://www.cve.org/CVERecord?id=CVE-2021-46143 Référence CVE CVE-2022-0330 https://www.cve.org/CVERecord?id=CVE-2022-0330 Référence CVE CVE-2022-0492 https://www.cve.org/CVERecord?id=CVE-2022-0492 Référence CVE CVE-2022-0778 https://www.cve.org/CVERecord?id=CVE-2022-0778 Référence CVE CVE-2022-0847 https://www.cve.org/CVERecord?id=CVE-202

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-014112Babel におけるパストラバーサルの脆弱性

Babel には、パストラバーサルの脆弱性が存在します。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
n/a
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 20 Oct 2021 · Last source change 4 Aug 2024, 03:38 UTC · CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-0032
Product sourceUnavailable
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2021-0032↗Patch or update reference↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-42771 · cve.blacktree.nl