CVE-2022-28734 | Out-of-bounds write when handling split HTTP headers

Out-of-bounds write when handling split HTTP headers; When handling split HTTP headers, GRUB2 HTTP code accidentally moves its internal data buffer point by one position. This can lead to a out-of-bound write further when parsing the HTTP request, writing a NULL byte past the buffer. It's conceivable that an attacker controlled set of packets can lead to corruption of the GRUB2's internal memory metadata.

Published: 2023-07-19 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-28734 is rated Moderate Risk (55.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.13%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-28734

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.15% 1.13% +0.98%
2 2026-05-16 0.14% 0.15% +0.01%
3 2025-11-21 — 0.14% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-28734

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.9 [email protected]
7.0 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 4.7 [email protected]

Weakness enumeration for CVE-2022-28734

OS Trackers for CVE-2022-28734

vendor priority summary link
debian not yet assigned CVE-2022-28734 not yet assigned priority: Debian including 1 source packages (grub2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-28734
gentoo high CVE-2022-28734: 1 GLSA(s) (202209-12), 1 atom(s) (sys-boot/grub); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-28734
redhat medium — https://access.redhat.com/security/cve/CVE-2022-28734
suse high — https://www.suse.com/security/cve/CVE-2022-28734/
ubuntu medium CVE-2022-28734 medium priority: Ubuntu including 3 source packages (grub2, grub2-signed, grub2-unsigned), 40 status rows across 14 suites (bionic, focal, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 24, released 7, ignored 3, needs-triage 3, needed 2, DNE 1. https://ubuntu.com/security/CVE-2022-28734

Affected software / configurations for CVE-2022-28734

Vendor Product Version Raw CPE
gnu grub2 >= 2.00, < 2.06-3 cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*
netapp active_iq_unified_manager — cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*

References for CVE-2022-28734

cvelogic Threat Intelligence