HOMEVULNERABILITIESCVE-2021-31323
MEDIUM

CVE-2021-31323

CWE-787Published: May 18, 2021· Updated: Jun 17, 2026

5.5
CVSS v3.1

Official Description

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Heap Buffer Overflow in the LottieParserImpl::parseDashProperty function of their custom fork of the rlottie library. A remote attacker might be able to access heap memory out-of-bounds on a victim device via a malicious animated sticker.

NVD Source

Technical Analysis

CVE-2021-31323 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 5.5.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected Vendors & Products

telegram1 product(s)
telegram
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://www.shielder.it/advisories/telegram-rlottie-lottieparserimpl-parsedashproperty-heap-buffer-overflow/
ADVISORYhttps://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/
ADVISORYhttps://www.shielder.it/advisories/telegram-rlottie-lottieparserimpl-parsedashproperty-heap-buffer-overflow/
ADVISORYhttps://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/

All References (4)

→
https://www.shielder.it/advisories/telegram-rlottie-lottieparserimpl-parsedashproperty-heap-buffer-overflow/Exploit · Third Party Advisory
→
https://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/Exploit · Third Party Advisory
→
https://www.shielder.it/advisories/telegram-rlottie-lottieparserimpl-parsedashproperty-heap-buffer-overflow/Exploit · Third Party Advisory
→
https://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/Exploit · Third Party Advisory

Quick Facts

CVE IDCVE-2021-31323
CVSS Score5.5 / 10
SeverityMEDIUM
WeaknessCWE-787
CISA KEVNo
Affected1 vendor(s)
PublishedMay 18, 2021

Related CVEs (CWE-787)

CVE-2009-2466
10.0
CVE-2018-17160
10.0
CVE-2004-1287
10.0
CVE-2026-4746
10.0
CVE-2012-0751
10.0
CVE-2018-3991
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-31323 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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