Security readout for executives and security teams
Plain-English summary
CVE-2021-47793 is a denial-of-service issue in Telegram Desktop 2.9.2. A specially oversized message can crash the desktop application. This affects availability of the client, not confidentiality or integrity based on the provided CVSS data. Public proof-of-concept material exists, but the sources do not show active exploitation.
Executive priority
Prioritize remediation where Telegram Desktop is business-critical or broadly deployed. This is not a data-theft issue based on current sources, but it can disrupt user communications. Address through endpoint software governance and version control rather than emergency incident response unless crashes are observed.
Technical view
Telegram Desktop 2.9.2 is reported vulnerable to resource-consumption denial of service, mapped to CWE-770. The CVSS v3.1 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, score 7.5. The described trigger is an oversized message payload causing application crash. No affected versions beyond 2.9.2 are identified in the supplied sources.
Likely exposure
Exposure is limited to environments running Telegram Desktop 2.9.2. The impact is application availability: users may lose access to the desktop client until it is restarted or otherwise recovered. Server-side Telegram services and other Telegram products are not identified as affected in the provided sources.
Exploitation context
A public ExploitDB entry and VulnCheck advisory describe proof-of-concept conditions. The CVE is not listed as CISA KEV in the supplied data, and no cited source states active exploitation. Treat this as a known public DoS technique, not confirmed in-the-wild exploitation.
Researcher notes
The record’s key evidence is third-party advisory and ExploitDB PoC references. The CVE was published in 2026 for a Telegram Desktop 2.9.2 issue titled from 2021. Sources do not identify a vendor advisory, fixed version, or broader affected range, so validation should avoid assuming impact beyond 2.9.2.
Mitigation direction
- Inventory endpoints for Telegram Desktop 2.9.2.
- Check Telegram guidance and release notes for fixed or current versions.
- Upgrade away from version 2.9.2 where business use requires Telegram Desktop.
- Restrict or remove unauthorized Telegram Desktop installations if not business-approved.
Validation and detection
- Confirm installed Telegram Desktop versions through endpoint inventory.
- Review application crash logs for Telegram Desktop availability incidents.
- Verify users no longer run version 2.9.2 after remediation.
- Track vendor or advisory updates for affected-version clarification.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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-770: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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 lookupCVE-2021-47793 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- ExploitDB-50247CVE reference · exploit
- Official Telegram HomepageCVE reference · product
- VulnCheck Advisory: Telegram Desktop 2.9.2 - Denial of Service (PoC)CVE reference · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Allocation of Resources Without Limits or Throttling
Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.