CVE-2020-24338
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn issue was discovered in picoTCP through 1.7.0. The DNS domain name record decompression functionality in pico_dns_decompress_name() in pico_dns_common.c does not validate the compression pointer offset values with respect to the actual data present in a DNS response packet, causing out-of-bounds writes that lead to Denial-of-Service and Remote Code Execution.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidencepicoTCP versions through 1.7.0 contain a critical vulnerability in the DNS domain name record decompression function pico_dns_decompress_name(). The function fails to validate compression pointer offset values against the actual data length in DNS response packets, allowing out-of-bounds memory writes that can cause denial of service or remote code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 1.7.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify picoTCP presenceSearch for picoTCP source files, libraries, or binaries in the environment. Look for files named pico_tcp.c, picotcp.h, libpicotcp, or products known to embed picoTCP.Affected if picoTCP is found in the environment
-
Determine picoTCP versionCheck the version string in picoTCP source files, library headers, or firmware that includes picoTCP. Look for version definitions like PICO_VERSION or version comments in source files.Affected if The version is 1.7.0 or lower, or no version is found (implying older release)
-
Verify DNS parsing is enabledCheck if DNS functionality is compiled or enabled in the picoTCP build configuration. Look for PICO_DNS, PICO_SUPPORT_DNS, or similar build flags in config files or makefiles.Affected if DNS parsing support is enabled in the build
-
Inspect DNS decompression codeIf source code is available, examine the pico_dns_decompress_name() function for bounds checking on compression pointer offsets. Verify if offset validation against packet length exists before memory access.Affected if The code lacks proper bounds validation on DNS compression pointers
You are affected if picoTCP version 1.7.0 or lower is present with DNS parsing functionality enabled, and the pico_dns_decompress_name() function does not validate compression pointer offsets against packet boundaries.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataIf a patched version is available, upgrade immediately. Otherwise, implement strict bounds validation on DNS compression pointer offsets before decompression, ensuring pointers do not exceed packet boundaries. Consider disabling DNS parsing or adding network-level filtering as a temporary compensating control.
- Consultation6.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,816.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-24338 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-24338 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data