Security readout for executives and security teams
Plain-English summary
libcoap before commit 30db3ea can overflow a stack buffer while resolving attacker-controlled hostnames. In applications with proxy request handling enabled, a remote unauthenticated attacker could crash the service and might achieve code execution depending on memory protections. Organizations using libcoap for CoAP proxying should prioritize inventory and vendor update review.
Executive priority
Treat as high priority where libcoap proxy functionality is internet-facing or used in critical services. The main business risk is service outage, with possible code execution not ruled out by sources. Prioritize exposed proxy deployments first.
Technical view
The flaw is a CWE-121 stack-based buffer overflow in libcoap address resolution. Hostname data can be copied into a fixed 256-byte stack buffer without proper bounds checking. Sources identify versions through 4.3.5 before commit 30db3ea as affected, with CVSS 4.0 score 8.2 and required proxy-code-path exposure.
Likely exposure
Exposure appears limited to applications using libcoap versions up to 4.3.5 before commit 30db3ea with proxy request handling enabled. Systems that include libcoap but do not expose the proxy logic are not shown as reachable in the provided bundle.
Exploitation context
The bundle does not cite active exploitation and marks KEV false. The issue is remotely reachable with no privileges or user interaction, but the attack path requires enabled proxy handling. Confirmed impact is denial of service; remote code execution is described as potential and environment-dependent.
Researcher notes
Key uncertainty is exploitability beyond crash. The advisory ties reachability to proxy logic, so validation should focus on code-path exposure, build flags, and deployed commit level. Avoid assuming all libcoap consumers are vulnerable without proxy handling evidence.
Mitigation direction
- Update libcoap to a version containing commit 30db3ea or later vendor guidance.
- Disable or restrict libcoap proxy request handling where it is not required.
- Limit network exposure to CoAP proxy services using segmentation and access controls.
- Review compiler and runtime memory protections for affected deployments.
Validation and detection
- Inventory applications and firmware that link or bundle libcoap.
- Confirm deployed libcoap version or commit is after 30db3ea.
- Check whether proxy request handling is enabled and reachable remotely.
- Review service logs for unexpected crashes in proxy hostname resolution paths.
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-121: 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2025-34468 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
- High
- CVSS
- 8.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
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.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
8.2HighVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/obgm/libcoap/pull/1737CVE reference, VulnCheck · issue-tracking
- https://github.com/obgm/libcoap/commit/30db3eaCVE reference, VulnCheck · patch
- https://libcoap.net/CVE reference, VulnCheck · product
- https://www.vulncheck.com/advisories/libcoap-stack-based-buffer-overflow-in-address-resolution-dos-or-potential-rceCVE reference, VulnCheck · third-party-advisory
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.
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.