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CVE Record

CVE-2021-43300: Stack overflow in PJSUA API when calling pjsua_recorder_create.

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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-43300 is a stack overflow in PJSIP’s PJSUA recorder creation path. If an application lets an attacker influence the recorder filename, that input may overflow a fixed-size stack buffer. Business urgency depends on whether your voice, SIP, or embedded communications software uses this API with untrusted input.

Executive priority

Treat this as a targeted dependency remediation item, not a broad emergency. Prioritize systems providing SIP, VoIP, or recording features, especially internet-facing or customer-facing services. Escalate if untrusted users can influence recording filenames.

Technical view

The CVE describes CWE-121 in pjsua_recorder_create: an attacker-controlled filename is copied into a fixed-size stack buffer without size validation. Sources do not provide CVSS, exact affected versions, or confirmed exploitability details. Debian issued security updates for pjproject and related packages referencing this issue.

Likely exposure

Likely exposure is in applications or appliances embedding Teluu PJSIP/PJSUA, especially SIP, VoIP, conferencing, or telephony software that creates recordings from user-influenced filenames. Debian advisories mention pjproject, Asterisk, and Ring updates, so packaged deployments should be checked.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. Exploitation would require a reachable code path where an attacker can control the filename passed to pjsua_recorder_create. Public evidence in the bundle is insufficient to claim real-world exploitation.

Researcher notes

Key uncertainty is version scope: the bundle lists Teluu pjsip with unspecified versions and no CVSS. The vulnerability is memory corruption in a library API, so impact depends heavily on caller behavior, build hardening, and whether filename input crosses a trust boundary.

Mitigation direction

  • Check PJSIP/PJProject vendor guidance and apply available fixes.
  • Apply relevant Debian security updates for pjproject if using Debian packages.
  • Review Asterisk and Ring package updates if those deployments are present.
  • Restrict or validate recorder filenames before passing them to PJSUA APIs.
  • Reduce exposure of recording features reachable by untrusted users.

Validation and detection

  • Inventory systems and applications using PJSIP, PJProject, or PJSUA.
  • Identify calls to pjsua_recorder_create in internal code or vendor integrations.
  • Confirm recorder filenames cannot be controlled by untrusted users.
  • Check deployed package versions against Debian DSA and DLA advisories.
  • Document any compensating filename validation or feature restrictions.
Prepared
Confidence
medium
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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

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cwe · low confidence lookup

CWE-121: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-43300 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
0Timeline events
0ADP providers
7Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
teluupjsipunspecifiedListed
Weakness

CWE details

CWE-121

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-121 · source CWE mapping

Stack-based Buffer Overflow

Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs