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HIGH

CVE-2025-69420

Missing ASN1_TYPE validation in TS_RESP_verify_response() function

CVSS v3

7.5

HIGH

EPSS Score

0.9 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

none

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • opensslAlmaLinux:10all versions · fixed in 1:3.5.1-7.el10_1.alma.1and 3 other packages
  • opensslAlmaLinux:9all versions · fixed in 1:3.5.1-7.el9_7and 3 other packages

Vendor advisories

  • CVE-2025-69420 Red Hat Product Security134 products fixed · 60 known affected

    openssl: OpenSSL: Denial of Service via malformed TimeStamp Response

    edk2-aarch64 as a component of Red Hat Enterprise Linux 10 · edk2-ovmf as a component of Red Hat Enterprise Linux 10 · edk2-tools as a component of Red Hat Enterprise Linux 10

  • RHSA-2026:82857 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.18.2

  • RHSA-2026:82372 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.18.2

  • RHSA-2026:82354 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.18.2

  • RHSA-2026:82347 Red Hat Product Security8 products fixed

    Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.18.2

  • RHSA-2026:7261 Red Hat Product Security13 products fixed

    Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

9 more advisories

Full record on NVD

Description

Issue summary: A type confusion vulnerability exists in the TimeStamp Response verification code where an ASN1_TYPE union member is accessed without first validating the type, causing an invalid or NULL pointer dereference when processing a malformed TimeStamp Response file. Impact summary: An application calling TS_RESP_verify_response() with a malformed TimeStamp Response can be caused to dereference an invalid or NULL pointer when reading, resulting in a Denial of Service. The functions ossl_ess_get_signing_cert() and ossl_ess_get_signing_cert_v2() access the signing cert attribute value without validating its type. When the type is not V_ASN1_SEQUENCE, this results in accessing invalid memory through the ASN1_TYPE union, causing a crash. Exploiting this vulnerability requires an attacker to provide a malformed TimeStamp Response to an application that verifies timestamp responses. The TimeStamp protocol (RFC 3161) is not widely used and the impact of the exploit is just a Denial of Service. For these reasons the issue was assessed as Low severity. The FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the TimeStamp Response implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue. OpenSSL 1.0.2 is not affected by this issue.

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-01-27
Last Modified
2026-02-02

Frequently asked questions

What is CVE-2025-69420?

Issue summary: A type confusion vulnerability exists in the TimeStamp Response verification code where an ASN1_TYPE union member is accessed without first validating the type, causing an invalid or NULL pointer dereference when processing a malformed TimeStamp Response file. Impact summary: An application calling TS_RESP_verify_response() with a malformed TimeStamp Response can be caused to dereference an invalid or NULL pointer when reading, resulting in a Denial of Service. The functions ossl_ess_get_signing_cert() and ossl_ess_get_signing_cert_v2() access the signing cert attribute value without validating its type. When the type is not V_ASN1_SEQUENCE, this results in accessing invalid memory through the ASN1_TYPE union, causing a crash. Exploiting this vulnerability requires an attacker to provide a malformed TimeStamp Response to an application that verifies timestamp responses. The TimeStamp protocol (RFC 3161) is not widely used and the impact of the exploit is just a Denial of Service. For these reasons the issue was assessed as Low severity. The FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the TimeStamp Response implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue. OpenSSL 1.0.2 is not affected by this issue.

Is CVE-2025-69420 actively exploited?

Active exploitation of CVE-2025-69420 has not been confirmed. Its EPSS score was 0.9% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2025-69420?

CVE-2025-69420 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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