How severe is CVE-2021-43300?

CVE-2021-43300 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-43300 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43300?

CVE-2021-43300 primarily affects Teluu Pjsip. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-43300?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-43300 published?

CVE-2021-43300 was published on 2022-02-16 and last updated on 2026-06-17.

CVE-2021-43300

CVE-2021-43300 is a critical-severity vulnerability in Teluu Pjsip with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-121.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-121
Affected product: Teluu Pjsip
Published: 2022-02-16
Last modified: 2026-06-17

Description

Stack overflow in PJSUA API when calling pjsua_recorder_create. An attacker-controlled 'filename' argument may cause a buffer overflow since it is copied to a fixed-size stack buffer without any size validation.

Frequently asked questions

What is CVE-2021-43300?: Stack overflow in PJSUA API when calling pjsua_recorder_create. An attacker-controlled 'filename' argument may cause a buffer overflow since it is copied to a fixed-size stack buffer without any size validation.
How severe is CVE-2021-43300?: CVE-2021-43300 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-43300 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43300?: CVE-2021-43300 primarily affects Teluu Pjsip. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-43300?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-43300 published?: CVE-2021-43300 was published on 2022-02-16 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:teluu:pjsip:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

More vulnerabilities in Teluu Pjsip

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CVE-2021-43299 — Critical (CVSS 9.8): Stack overflow in PJSUA API when calling pjsua_player_create. An attacker-controlled 'filename' argument may cause a…
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