Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 2.81% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2020
CVE-2020-17437High confidence
An issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products
Unknown · Unknown
8.2HighCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productHigh technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 9 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 9 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Siemens ProductCERT: 9 affected or under-investigation product states without a fixed product state in the same current advisory
Distribution package intelligence
4 package statesRelease-specific package status
Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | open-iscsi | Vendor fix publishedDebian records a fixed source-package version for this release. | 2.1.3-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | open-iscsi | Vendor fix publishedDebian records a fixed source-package version for this release. | 2.1.3-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | open-iscsi | Vendor fix publishedDebian records a fixed source-package version for this release. | 2.1.3-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | open-iscsi | Vendor fix publishedDebian records a fixed source-package version for this release. | 2.1.3-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
Direct vendor intelligence
1 currentAuthoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
SSA-541018 · CSAF 2.0 · revision 6 · finalSiemens ProductCERTSSA-541018: Embedded TCP/IP Stack Vulnerabilities (AMNESIA:33) in SENTRON PAC / 3VA Devices (Part 2)
The vendor explicitly identifies these products as affected by this CVE.
- SENTRON 3VA COM100/800
- SENTRON 3VA DSP800
- SENTRON PAC2200 (with CLP Approval)
- SENTRON PAC2200 (with MID Approval)
- SENTRON PAC2200 (without MID Approval)
- SENTRON PAC3200
- SENTRON PAC3200T
- SENTRON PAC3220
- SENTRON PAC4200
- Summary
- The TCP/IP stack (uIP) in affected devices is vulnerable to out-of-bounds write when processing TCP packets with urgent pointer (URG) where the location of the TCP data payload is calculated improperly. (FSCT-2020-0018) An attacker located in the same network could trigger a Denial-of-Service condition on the device by sending a specially crafted IP packet.
- Remediation
- Update to V4.4.1 or later version
High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 9 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
An issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products. When the Urgent flag is set in a TCP packet, and the stack is configured to ignore the urgent data, the stack attempts to use the value of the Urgent pointer bytes to separate the Urgent data from the normal data, by calculating the offset at which the normal data should be present in the global buffer. However, the length of this offset is not checked; therefore, for large values of the Urgent pointer bytes, the data pointer can point to memory that is way beyond the data buffer in uip_process in uip.c.
What
An issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products. When the Urgent flag is set in a TCP packet, and the stack is configured to ignore the urgent data, the stack attempts to use the value of the Urgent pointer bytes to separate the Urgent data from the normal data, by calculating the offset at which the normal data should be present in the global buffer. However, the length of this offset is not checked; therefore, for large values of the Urgent pointer bytes, the data pointer can point to memory that is way beyond the data buffer in uip_process in uip.c.
Why
A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
An issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products. When the Urgent flag is set in a TCP packet, and the stack is configured to ignore the urgent data, the stack attempts to use the value of the Urgent pointer bytes to separate the Urgent data from the normal data, by calculating the offset at which the normal data should be present in the global buffer. However, the length of this offset is not checked; therefore, for large values of the Urgent pointer bytes, the data pointer can point to memory that is way beyond the data buffer in uip_process in uip.c.
Why
A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Out-of-bounds Write → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-787 ↗
CWE-787: Out-of-bounds Write. The product writes data past the end, or before the beginning, of the intended buffer.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CLowConfidentiality impact: A successful attack can cause a limited loss.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix availability varies by product
- Affected
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 11 Dec 2020 · Last source change 4 Aug 2024, 13:53 UTC · CWE-787 · Out-of-bounds Write
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2020-9390
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceNIST NVD
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
- Affected versionsThe structured affected or fixed version information changed.Siemens ProductCERT ↗
- Before
- n/a · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
- After
- n/a · Fixed: Update to V4.4.1 or later version
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.