Security readout for executives and security teams
Plain-English summary
CVE-2021-39545 is a denial-of-service flaw in sela through 20200412. A malformed or otherwise attacker-controlled input reaching the Rice decoder can trigger a NULL pointer dereference and crash the affected process. The available sources do not provide CVSS scoring, affected CPEs, or a confirmed fixed version.
Executive priority
Treat as a targeted availability risk, not proven remote code execution. Prioritize if sela processes untrusted files or service traffic in business-critical workflows; otherwise handle through normal dependency risk management.
Technical view
The CVE describes a NULL pointer dereference in rice::RiceDecoder::process() in rice_decoder.c. Impact is limited in the source record to denial of service. The affected scope is stated as sela through 20200412, but the CVE bundle lists vendor/product/CPE as n/a and does not identify a patch.
Likely exposure
Exposure is likely limited to systems or applications that embed or run sela through 20200412 and process inputs that reach the Rice decoder. Internet exposure depends on whether those inputs are accepted from untrusted users or automated workflows.
Exploitation context
The bundle does not cite CISA KEV inclusion or active exploitation. The public GitHub issue is referenced as disclosure evidence, but no source here confirms weaponized exploitation, exploitation in the wild, or a public patch.
Researcher notes
Evidence is sparse: no CVSS, CWE, CPE, exploit status, or fixed release is provided in the bundle. Analysis should remain anchored to the named function, NULL dereference class, sela through 20200412 scope, and denial-of-service impact only.
Mitigation direction
- Inventory any use of sela through 20200412.
- Check the upstream project issue for fix or maintainer guidance.
- Restrict untrusted inputs from reaching the affected decoder.
- Run affected processing in a supervised, restartable, least-privilege context.
- Monitor for crashes tied to rice_decoder.c or RiceDecoder processing.
Validation and detection
- Confirm whether sela is present in source, builds, or bundled dependencies.
- Identify deployed versions and compare against through 20200412.
- Review whether external users can supply decoder inputs.
- Check crash telemetry for NULL pointer dereference symptoms.
- Track the referenced GitHub issue for resolution details.
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.
CVE-2021-39545 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/sahaRatul/sela/issues/31CVE reference · x_refsource_MISC
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.