Security readout for executives and security teams
Plain-English summary
Older Telegram clients could mishandle a malicious animated sticker and read or touch memory outside expected bounds. This is an endpoint risk for users running affected Telegram versions, not a server breach by itself.
Executive priority
Treat this as a targeted endpoint hygiene issue. Prioritize version inventory and upgrades for users who rely on Telegram for business-sensitive communications, especially on unmanaged mobile or macOS devices.
Technical view
CVE-2021-31318 is a type confusion in LOTCompLayerItem::LOTCompLayerItem in Telegram's custom rlottie fork. A malicious animated sticker might trigger out-of-bounds heap memory access on Telegram Android before 7.1.0 (2090), iOS before 7.1, and macOS before 7.1.
Likely exposure
Exposure is most likely on unmanaged or legacy endpoints still running Telegram Android, iOS, or macOS versions below the stated 7.1 release line. Organizations without mobile app inventory may not know whether users remain exposed.
Exploitation context
The sources describe remote attack surface through animated stickers but do not cite active exploitation. CISA KEV is false in the supplied bundle. The public evidence says memory out-of-bounds access may be possible, but does not prove reliable code execution.
Researcher notes
The evidence identifies the vulnerable function and attack vector but provides no CVSS, CWE, or confirmed exploitation status in the supplied bundle. Avoid assuming impact beyond possible out-of-bounds heap memory access unless additional vendor or exploit evidence is available.
Mitigation direction
- Upgrade Telegram Android to 7.1.0 (2090) or later.
- Upgrade Telegram iOS and macOS to 7.1 or later.
- Restrict unsupported Telegram versions on managed devices where policy allows.
- Check Telegram or vendor guidance for any newer hardening advice.
Validation and detection
- Inventory Telegram versions on managed Android, iOS, and macOS endpoints.
- Confirm no managed devices run below the affected version thresholds.
- Review EDR or MDM telemetry for legacy Telegram installations.
- Track exceptions for unmanaged or personally owned devices separately.
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.
CVE-2021-31318 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/CVE reference · x_refsource_MISC
- https://www.shielder.it/advisories/telegram-rlottie-lotcomplayeritem-lotcomplayeritem-type-confusion/CVE reference · x_refsource_MISC
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.