Apache Log4j SMTP Appender SMTPS certificate validation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.7$5k-$25k0.00

Summaryinfo

A vulnerability was found in Apache Log4j SMTP Appender. It has been declared as critical. The affected element is an unknown function of the component SMTPS Handler. Executing a manipulation can lead to certificate validation. This vulnerability appears as CVE-2020-9488. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability classified as problematic was found in Apache Log4j SMTP Appender (version now known). This vulnerability affects some unknown processing of the component SMTPS Handler. The manipulation with an unknown input leads to a certificate validation vulnerability. The CWE definition for the vulnerability is CWE-295. The product does not validate, or incorrectly validates, a certificate. As an impact it is known to affect confidentiality. CVE summarizes:

Improper validation of certificate with host mismatch in Apache Log4j SMTP appender. This could allow an SMTPS connection to be intercepted by a man-in-the-middle attack which could leak any log messages sent through that appender. Fixed in Apache Log4j 2.12.3 and 2.13.1

The weakness was presented 04/27/2020 (Website). The advisory is shared for download at issues.apache.org. This vulnerability was named CVE-2020-9488 since 03/01/2020. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 05/29/2026). The MITRE ATT&CK project declares the attack technique as T1587.003.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

See VDB-158161, VDB-158162, VDB-158163 and VDB-158182 for similar entries. Once again VulDB remains the best source for vulnerability data.

Productinfo

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.7
VulDB Meta Temp Score: 3.7

VulDB Base Score: 3.7
VulDB Temp Score: 3.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 3.7
NVD Vector: 🔍

ADP CISA Base Score: 3.7
ADP CISA Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Certificate validation
CWE: CWE-295 / CWE-287
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

03/01/2020 🔍
04/27/2020 +57 days 🔍
04/28/2020 +1 days 🔍
05/29/2026 +2222 days 🔍

Sourcesinfo

Vendor: apache.org

Advisory: DLA 2852-1
Status: Not defined
Confirmation: 🔍

CVE: CVE-2020-9488 (🔍)
GCVE (CVE): GCVE-0-2020-9488
GCVE (VulDB): GCVE-100-154468
See also: 🔍

Entryinfo

Created: 04/28/2020 11:52
Updated: 05/29/2026 22:41
Changes: 04/28/2020 11:52 (38), 04/28/2020 11:57 (17), 10/13/2020 15:20 (1), 06/03/2024 14:17 (17), 05/29/2026 22:41 (12)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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