Security readout for executives and security teams
Plain-English summary
CVE-2021-43303 is a buffer overflow in Teluu PJSIP's PJSUA API. The problem appears when pjsua_call_dump is called with an output buffer smaller than 128 characters, which may overflow despite the supplied maxlen value.
Executive priority
Treat this as a dependency hygiene issue for communications software. It is not cited as actively exploited, but memory corruption in SIP/telephony components can be business-relevant where voice infrastructure is exposed or mission-critical.
Technical view
The CVE describes CWE-120 in pjproject/pjsip: pjsua_call_dump may write past a caller-provided output buffer under 128 bytes. Source data does not provide CVSS, exact affected versions, or proof of remote reachability.
Likely exposure
Exposure is most likely in systems or applications that embed pjproject/pjsip and call pjsua_call_dump. Debian advisories cite updates for pjproject and downstream packages such as asterisk and ring, indicating dependency-level exposure may matter.
Exploitation context
No CISA KEV listing or cited source indicates active exploitation. Practical exploitation depends on whether an application exposes a path where this API is called with an undersized or attacker-influenced buffer.
Researcher notes
The public bundle lacks exact vulnerable version ranges, CVSS, patch identifiers, and exploit details. Assessment should focus on vendor advisories, distribution package changelogs, and whether reachable application code can invoke pjsua_call_dump unsafely.
Mitigation direction
- Apply vendor or distribution security updates for pjproject/pjsip.
- Update Debian packages referenced in applicable DSA or DLA advisories.
- Review applications embedding pjproject for bundled or statically linked copies.
- Check vendor guidance before assuming a workaround exists.
- Prioritize systems providing voice, SIP, or telephony services.
Validation and detection
- Inventory installed pjproject, pjsip, asterisk, and ring packages.
- Identify applications that statically embed pjproject/pjsip.
- Confirm patched versions against vendor or distribution advisories.
- Review code paths calling pjsua_call_dump for undersized buffers.
- Check vulnerability scanners for CVE-2021-43303 findings.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-120: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-43303 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/pjsip/pjproject/security/advisories/GHSA-qcvw-h34v-c7r9CVE reference
- [debian-lts-announce] 20220328 [SECURITY] [DLA 2962-1] pjproject security updateCVE reference · mailing-list
- [debian-lts-announce] 20221117 [SECURITY] [DLA 3194-1] asterisk security updateCVE reference · mailing-list
- DSA-5285CVE reference · vendor-advisory
- [debian-lts-announce] 20230829 [SECURITY] [DLA 3549-1] ring security updateCVE reference · mailing-list
- https://lists.debian.org/debian-lts-announce/2024/09/msg00030.htmlCVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.