How severe is CVE-2021-43303?

CVE-2021-43303 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-2021-43303 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-2021-43303?

CVE-2021-43303 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-2021-43303?

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-2021-43303 published?

CVE-2021-43303 was published on 2022-02-16 and last updated on 2026-06-17.

CVE-2021-43303

CVE-2021-43303 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-120.

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-120
Affected product: Teluu Pjsip
Published: 2022-02-16
Last modified: 2026-06-17

Description

Buffer overflow in PJSUA API when calling pjsua_call_dump. An attacker-controlled 'buffer' argument may cause a buffer overflow, since supplying an output buffer smaller than 128 characters may overflow the output buffer, regardless of the 'maxlen' argument supplied

Frequently asked questions

What is CVE-2021-43303?: Buffer overflow in PJSUA API when calling pjsua_call_dump. An attacker-controlled 'buffer' argument may cause a buffer overflow, since supplying an output buffer smaller than 128 characters may overflow the output buffer, regardless of the 'maxlen' argument supplied
How severe is CVE-2021-43303?: CVE-2021-43303 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-2021-43303 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-2021-43303?: CVE-2021-43303 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-2021-43303?: 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-2021-43303 published?: CVE-2021-43303 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-2021-43301 — Critical (CVSS 9.8): Stack overflow in PJSUA API when calling pjsua_playlist_create. An attacker-controlled 'file_names' argument may cause…
CVE-2021-43300 — Critical (CVSS 9.8): Stack overflow in PJSUA API when calling pjsua_recorder_create. An attacker-controlled 'filename' argument may cause a…
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…
CVE-2017-16872 — Critical (CVSS 9.8): An issue was discovered in Teluu pjproject (pjlib and pjlib-util) in PJSIP before 2.7.1. Parsing the numeric header…

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