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CVE Record

CVE-2020-36315: In RELIC before 2020-08-01, RSA PKCS#1 v1.5 signature forgery can occur because certain checks of the paddi...

In RELIC before 2020-08-01, RSA PKCS#1 v1.5 signature forgery can occur because certain checks of the padding (and of the first two bytes) are inadequate. NOTE: this requires that a low public exponent (such as 3) is being used. The product, by default, does not generate RSA keys with such a low number.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

RELIC versions before 2020-08-01 may incorrectly accept forged RSA PKCS#1 v1.5 signatures in a narrow configuration. The issue matters where RELIC verifies signatures using low public exponent RSA keys, such as exponent 3. RELIC reportedly does not generate such low-exponent keys by default.

Executive priority

Treat this as a targeted dependency and cryptography review item, not an internet-wide emergency based on available evidence. Prioritize systems where RELIC verifies trust decisions, software updates, identities, or signed messages using externally supplied RSA keys.

Technical view

The CVE describes inadequate checks on RSA PKCS#1 v1.5 signature padding and the first two bytes in RELIC before 2020-08-01. The forgery condition requires a low public exponent. No CVSS, CWE, affected CPEs, or product-specific downstream impact are provided in the source bundle.

Likely exposure

Exposure is most likely in software embedding RELIC before 2020-08-01 for RSA PKCS#1 v1.5 signature verification while accepting low-exponent public keys. The source bundle does not identify downstream products, package versions, or CPEs, so dependency inventory is required.

Exploitation context

The source bundle does not show CISA KEV listing or active exploitation. Public details indicate a cryptographic signature-forgery condition with a specific prerequisite: low public exponent RSA. Exploit maturity and real-world abuse are not evidenced here.

Researcher notes

The strongest evidence is the CVE description and linked RELIC issue/commit references. Missing data includes CVSS, CWE, downstream affected products, exact fixed release naming, and exploitation evidence. The low-exponent prerequisite materially narrows practical exposure.

Mitigation direction

  • Upgrade RELIC to source after 2020-08-01 or the referenced fixing commit lineage.
  • Check vendor guidance for products that embed or statically link RELIC.
  • Reject or replace low public exponent RSA keys where operationally feasible.
  • Review PKCS#1 v1.5 signature validation dependencies for affected RELIC use.

Validation and detection

  • Inventory applications and libraries that include RELIC directly or transitively.
  • Confirm RELIC build date, commit, or source snapshot against the 2020-08-01 boundary.
  • Identify RSA PKCS#1 v1.5 verification paths using RELIC.
  • Check whether accepted RSA public keys include low exponents such as 3.
  • Document findings where downstream product impact cannot be confirmed from sources.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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CVE-2020-36315 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
0Timeline events
0ADP providers
5Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.