Summary
USN-4994-1 fixed several vulnerabilities in Apache. This update provides
the corresponding update for Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.
Original advisory details:
Antonio Morales discovered that the Apache mod_auth_digest module
incorrectly handled certain Digest nonces. A remote attacker could possibly
use this issue to cause Apache to crash, resulting in a denial of service.
(CVE-2020-35452)
Antonio Morales discovered that the Apache mod_session module incorrectly
handled certain Cookie headers. A remote attacker could possibly use this
issue to cause Apache to crash, resulting in a denial of service.
(CVE-2021-26690)
Christophe Jaillet discovered that the Apache mod_session module
incorrectly handled certain SessionHeader values. A remote attacker could
use this issue to cause Apache to crash, resulting in a denial of service,
or possibly execute arbitrary code. (CVE-2021-26691)
Christoph Anton Mitterer discovered that the new MergeSlashes configuration
option resulted in unexpected behaviour in certain situations.
(CVE-2021-30641)
Fixed packages 2
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · Pro 14.04 LTS Pro:14.04:LTS | apache2 | 2.4.7-1ubuntu4.22+esm1 |
| Ubuntu · Pro 16.04 LTS Pro:16.04:LTS | apache2 | 2.4.18-2ubuntu3.17+esm1 |
Vulnerabilities 4
-
Unscored —CVE-2020-35452 EPSS 53%
mod_auth_digest possible stack overflow by one nul byte
Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in mod_auth_digest. There is no report of this overflow being exploitable, nor the Apache HTTP Server team could create one, though some particular compile…
-
Unscored —
mod_session NULL pointer dereference
Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can cause a NULL pointer dereference and crash, leading to a possible Denial Of Service
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Unscored —CVE-2021-26691 EPSS 68%
Apache HTTP Server mod_session response handling heap overflow
In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server could cause a heap overflow
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Unscored —CVE-2021-30641 EPSS 52%
Unexpected URL matching with 'MergeSlashes OFF'
Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'