What is CVE-2021-30496?

CVE-2021-30496 is a medium-severity vulnerability in Telegram, classified under Stack-based Buffer Overflow. CVSS score: 5.7/10. Published 2021-04-20.

How severe is CVE-2021-30496?

Medium severity. CVSS v3 base score is 5.7 out of 10.

Is CVE-2021-30496 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Telegram

CVE-2021-30496

The Telegram app 7.6.2 for iOS allows remote authenticated users to cause a denial of service (application crash) if the victim pastes an attacker-supplied message (e.g., in the Persian language) into a channel or group. The crash occurs in MtProtoKitFramework. NOTE: the vendor's perspective is that "this behavior can't be considered a vulnerability."

Vulnerability class: Buffer Overflow

EPSS: 0.012 (64.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H.

Affected products

Telegram — versions 7.6.2
N/a — versions n/a

Weakness classification (CWE)

CWE-121 — Stack-based Buffer Overflow

Public proof-of-concept exploits

References

cve@mitre.org (Exploit, Third Party Advisory)
cve@mitre.org (Vendor Advisory)

Frequently asked questions

What is CVE-2021-30496?: CVE-2021-30496 is a medium-severity vulnerability in Telegram, classified under Stack-based Buffer Overflow. CVSS score: 5.7/10. Published 2021-04-20.
How severe is CVE-2021-30496?: Medium severity. CVSS v3 base score is 5.7 out of 10.
Is CVE-2021-30496 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.