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CVE Record

CVE-2020-27748: A flaw was found in the xdg-email component of xdg-utils-1.1.0-rc1 and newer.

A flaw was found in the xdg-email component of xdg-utils-1.1.0-rc1 and newer. When handling mailto: URIs, xdg-email allows attachments to be discreetly added via the URI when being passed to Thunderbird. An attacker could potentially send a victim a URI that automatically attaches a sensitive file to a new email. If a victim user does not notice that an attachment was added and sends the email, this could result in sensitive information disclosure. It has been confirmed that the code behind this issue is in xdg-email and not in Thunderbird.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a desktop information-disclosure issue in xdg-email. A malicious mailto link could cause Thunderbird to open a new email with a sensitive local file already attached. The user would still need to send the email, so the main risk is accidental data leakage after social engineering.

Executive priority

Treat this as a targeted desktop data-leakage risk, not a broad infrastructure emergency. Prioritize sensitive-user workstations and environments where local documents or secrets could be accidentally attached and emailed.

Technical view

xdg-email in xdg-utils 1.1.0-rc1 and newer can pass attachment behavior through mailto URIs to Thunderbird. The source bundle says the issue is in xdg-email, not Thunderbird. The mapped weakness is CWE-201, with confidentiality impact dependent on user interaction and local file accessibility.

Likely exposure

Exposure is most likely on Linux desktop endpoints using affected xdg-utils where xdg-email handles mailto URIs and Thunderbird is the mail client. This is not described as a remote server compromise path in the provided sources.

Exploitation context

The bundle does not show KEV listing or confirmed active exploitation. Practical abuse would require enticing a user to open a crafted mailto URI and then send the composed email without noticing the unexpected attachment.

Researcher notes

Evidence is limited in the provided bundle: no CVSS vector, no named fixed version, and no cited active exploitation. The core claim is specific to xdg-email passing attachment behavior to Thunderbird through mailto URI handling.

Mitigation direction

  • Check current vendor or distribution guidance for patched xdg-utils packages.
  • Prioritize desktop fleets where Thunderbird is the default mail client.
  • Train users to inspect attachments before sending email from mailto links.
  • Restrict or warn on untrusted mailto URI handling where feasible.

Validation and detection

  • Inventory xdg-utils versions on Linux desktop endpoints.
  • Confirm whether xdg-email is associated with mailto links.
  • Identify endpoints where Thunderbird is configured as the mail client.
  • Review vendor advisories for fixed package versions or backports.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-201: Information exposure and cloud metadata lookup

Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2020-27748 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/axdg-utilsxdg-utils-1.1.0-rc1Listed
Weakness

CWE details

CWE-201

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-201 · source CWE mapping

Insertion of Sensitive Information Into Sent Data

Insertion of Sensitive Information Into Sent Data represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs